MEXICO CITY (Reuters): Mexican railroad operator Ferromex has temporarily suspended operations of 60 trains on northbound routes, the company said on Tuesday, after nearly half a dozen deaths or injuries of migrants using the cargo trains to travel.

Ferromex, owned by conglomerate Grupo Mexico, said in a statement the presence of migrants in its railcars and rail yards had grown “significantly” in recent days, growing to more than 4,000 in several cities throughout the country.

“Due to this, Ferromex will temporarily suspend its operations on the affected routes to protect the physical integrity of the migrants and will be monitoring whatever measures authorities implement,” the rail operator said.

Ferromex added it had made its clients aware of the disruption the suspension would cause to supply chains and international trade.