Mexican authorities stepped up revisions along well-traveled routes for migrants in southern Mexico over the weekend, checking identifications, pulling migrants off public transport and intercepting four trucks packed with nearly 800 migrants.

The National Migration Institute said 1,000 immigration agents had been deployed in the north and south of Mexico. The deployment comes as Mexico faces heightened pressure from the U.S. to reduce the surge of mostly Central American migrants through its territory. Mexico plans to position 6,000 National Guard troops by Tuesday to its southern border with Guatemala.

More Images
A young man cries as he says that if he gets sent back to Honduras, he will be killed, while sitting with other migrants inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Behind is Honduran migrant Noe, 31, holding his 4-year-old daughter Marlene. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Mexican authorities stepped up revisions along well-traveled routes for migrants in southern Mexico over the weekend, checking identifications, pulling migrants off public transport and intercepting four trucks packed with nearly 800 migrants.

Seen through a section of pipe placed the middle of a road between two-way traffic, soldiers forming part of the National Guard stand guard at an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

The Mexican National Guard is a new security force created by President Andrés Manuel López Obrador, who took office Dec. 1. The security force is still taking shape and was originally established with the goal of stemming endemic violence. Last year saw the highest number of murders in at least 20 years in Mexico.

A soldier forming part of the National Guard is reflected in a slatted window while manning an immigration checkpoint north of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Migrants are routinely transported through Mexico in packed semis, sometimes in dangerous conditions without food or water or sufficient fresh air. Government video showed officials breaking the lock on the door of one cargo truck and helping migrants out.

A soldier forming part of the National Guard mans an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

A soldier forming part of the National Guard mans an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Honduran migrant Noe, 31, kisses his 4-year-old daughter Marlene as they wait inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Honduran migrant Noe, 31, kisses his 4-year-old daughter Marlene as they wait inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Soldiers forming part of the National Guard man an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. AP PhotoRebecca Blackwell)

Soldiers forming part of the National Guard man an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard walk at a migration checkpoint on the highway north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard walk at a migration checkpoint on the highway north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing armbands for Mexico's National Guard man a temporary immigration checkpoint where officials were look for migrants, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing armbands for Mexico's National Guard man a temporary immigration checkpoint where officials were look for migrants, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

People ride in the back of a pickup as they pass through a temporary immigration checkpoint manned by soldiers wearing armbands for Mexico's National Guard, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

People ride in the back of a pickup as they pass through a temporary immigration checkpoint manned by soldiers wearing armbands for Mexico's National Guard, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

A truck decorated with crosses that light up when the driver brakes, slows down as it passes through a checkpoint, manned by soldiers from the National Guard along with immigration officers and federal police, in Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

A truck decorated with crosses that light up when the driver brakes, slows down as it passes through a checkpoint, manned by soldiers from the National Guard along with immigration officers and federal police, in Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard man a migration checkpoint north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard man a migration checkpoint north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard board a truck to patrol back roads that migrants use to avoid a migration checkpoint, north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard board a truck to patrol back roads that migrants use to avoid a migration checkpoint, north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

The Associated Press saw nearly 10 armed soldiers at a checkpoint near Ciudad Cuauhtémoc, in Chiapas state, wearing black armbands to indicate they are part of the National Guard. The soldiers stopped vehicles while immigration officials checked identification and removed passengers without documents. At another checkpoint just north of Comitán in Chiapas, more than a dozen apparent National Guardsmen drove around backroads in the rain and dark, looking for migrants.

A young man cries as he says that if he gets sent back to Honduras, he will be killed, while sitting with other migrants inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Behind is Honduran migrant Noe, 31, holding his 4-year-old daughter Marlene. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

A young man cries as he says that if he gets sent back to Honduras, he will be killed, while sitting with other migrants inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Behind is Honduran migrant Noe, 31, holding his 4-year-old daughter Marlene. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

The Mexican National Guard is a new security force created by President Andrés Manuel López Obrador, who took office Dec. 1. The security force is still taking shape and was originally established with the goal of stemming endemic violence. Last year saw the highest number of murders in at least 20 years in Mexico. 

Outside Comitán on Sunday, some roadblocks and checkpoints were manned by multiple soldiers and police identifying as National Guard. Others were staffed in shifts by a single immigration agent.

In the Gulf coast state of Veracruz, the National Migration Institute said 791 people were taken Saturday to a migration facility and that drivers of the tractor-trailer trucks transporting them were arrested.

Seen through a section of pipe placed the middle of a road between two-way traffic, soldiers forming part of the National Guard stand guard at an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Seen through a section of pipe placed the middle of a road between two-way traffic, soldiers forming part of the National Guard stand guard at an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Migrants are routinely transported through Mexico in packed semis, sometimes in dangerous conditions without food or water or sufficient fresh air. Government video showed officials breaking the lock on the door of one cargo truck and helping migrants out.

The institute described the detentions and arrests in Veracruz as part of a strategy implemented by its new commissioner, Francisco Garduño. The former prisons director assumed the post Friday, taking over for a sociologist and academic.

A soldier forming part of the National Guard is reflected in a slatted window while manning an immigration checkpoint north of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

A soldier forming part of the National Guard is reflected in a slatted window while manning an immigration checkpoint north of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

A soldier forming part of the National Guard mans an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

A soldier forming part of the National Guard mans an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Honduran migrant Noe, 31, kisses his 4-year-old daughter Marlene as they wait inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Honduran migrant Noe, 31, kisses his 4-year-old daughter Marlene as they wait inside an immigration holding cell after being removed from a bus heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. (AP PhotoRebecca Blackwell)

Soldiers forming part of the National Guard man an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. AP PhotoRebecca Blackwell)

Soldiers forming part of the National Guard man an immigration checkpoint heading north out of Comitan, Chiapas state, Mexico, Sunday, June 16, 2019. Mexican President Andrés Manuel López Obrador said Saturday his country must help Central Americans fleeing poverty and violence, even as it increases security and revisions to deter migrants from passing through Mexico on route to the U.S. AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard walk at a migration checkpoint on the highway north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard walk at a migration checkpoint on the highway north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing armbands for Mexico's National Guard man a temporary immigration checkpoint where officials were look for migrants, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing armbands for Mexico's National Guard man a temporary immigration checkpoint where officials were look for migrants, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

People ride in the back of a pickup as they pass through a temporary immigration checkpoint manned by soldiers wearing armbands for Mexico's National Guard, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

People ride in the back of a pickup as they pass through a temporary immigration checkpoint manned by soldiers wearing armbands for Mexico's National Guard, just north of Ciudad Cuauhtemoc, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

A truck decorated with crosses that light up when the driver brakes, slows down as it passes through a checkpoint, manned by soldiers from the National Guard along with immigration officers and federal police, in Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

A truck decorated with crosses that light up when the driver brakes, slows down as it passes through a checkpoint, manned by soldiers from the National Guard along with immigration officers and federal police, in Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard man a migration checkpoint north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard man a migration checkpoint north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard board a truck to patrol back roads that migrants use to avoid a migration checkpoint, north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)

Soldiers wearing the armbands of Mexico's National Guard board a truck to patrol back roads that migrants use to avoid a migration checkpoint, north of Comitan, Chiapas State, Mexico, Saturday, June 15, 2019. Under pressure from the U.S. to slow the flow of migrants north, Mexico plans to deploy thousands of National Guard troops by Tuesday to its southern border region.(AP PhotoRebecca Blackwell)