French and Dutch police have arrested 23 suspected members of a criminal network that has smuggled as many as 10,000 migrants from France to Britain, according to the European police agency Europol.

The network was suspected of earning 70 million euros ($77.6 million) in profits by organizing illegal passages for migrants from Afghanistan, Syria, Iraq and Iran, Europol said Thursday.

The migrants traveled to Britain from around the western French cities of Le Mans and Poitiers. Many of them faced life-threatening conditions, hidden in refrigerator trucks crossing the English Channel by ferry or undersea train. As many as 20 migrants were held in each truck and each paid as much as 7,000 euros ($7,760) for the crossing, Europol said.

Relatives of Bui Thi Nhung sit next to her casket during a funeral ceremony inside Phu Thang church ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)

Relatives of Bui Thi Nhung sit next to her casket during a funeral ceremony inside Phu Thang church ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)

A suspect in the Netherlands collected those payments via an underground banking system, Europol said. Police seized firearms and vehicles in five searches, and the migrants found during the operation were taken to safety.

Ton van Lierop, a spokesman for Eurojust, said most of the arrests were Tuesday in France.

The operation came amid renewed attention to migrants risking their lives in trucks trying to cross the Channel after 39 Vietnamese trying to enter Britain died in October in a refrigerated truck container.

Bui Van Diep holds a portrait of his sister Bui Thi Nhung as her casket is being brought to Phu Thang church ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)

Bui Van Diep holds a portrait of his sister Bui Thi Nhung as her casket is being brought to Phu Thang church ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)

Relatives of Bui Thi Nhung gather around her casket at the family home ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)

Relatives of Bui Thi Nhung gather around her casket at the family home ahead of Nhung’s burial on Sunday, Dec. 1, 2019 in the village of Do Thanh, Vietnam. The body of 19-year old Nhung was among the last remains of the 39 Vietnamese who died while being smuggled in a truck to England last month that were repatriated to their home country on Saturday. (AP PhotoHau Dinh)