Relatives of nine U.S. dual citizens slaughtered in northern Mexico last month say President Andrés Manuel López Obrador prayed with them for the safety of the country and pledged to visit the region.

Julian LeBaron said Tuesday that during the Monday meeting at Mexico City’s National Palace, the president and his Cabinet assured him that “at least four” suspects have been detained in the Nov. 4 killings.

Three young mothers and six children were killed in the attack near the border of the northern states of Sonora and Chihuahua. Officials have said a drug cartel is suspected in the attack.

Julian LeBaron, center, embraces Erika Garcia, left, and another woman before a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Sunday, Dec. 1, 2019. LeBaron joined a protest on Reforma avenue, to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)

Julian LeBaron, center, embraces Erika Garcia, left, and another woman before a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Sunday, Dec. 1, 2019. LeBaron joined a protest on Reforma avenue, to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)

LeBaron said officials have confirmed to them that the killers filmed the attack themselves and set fire to an SUV in which one mother and her four children died.

Adriana LeBaron, left, Julian LeBaron, center, and Adrian LeBaron, right, stand during a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Monday, Dec. 1, 2019. The LeBaron's joined a protest on Reforma avenue to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)

Adriana LeBaron, left, Julian LeBaron, center, and Adrian LeBaron, right, stand during a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Monday, Dec. 1, 2019. The LeBaron's joined a protest on Reforma avenue to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)

 Julian LeBaron, left, walks with Adrian LeBaron before a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Sunday, Dec. 1, 2019. The men joined a protest on Mexico City's Reforma avenue to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)

Julian LeBaron, left, walks with Adrian LeBaron before a protest against the first year in office of Mexico's President Andres Manuel Lopez Obrador, in Mexico City, Sunday, Dec. 1, 2019. The men joined a protest on Mexico City's Reforma avenue to expressed anger and frustration over increasingly appalling incidents of violence, a stagnant economy and deepening political divisions in the country. (AP PhotoGinnette Riquelme)