A Mexican railway operator announced Tuesday it is temporarily suspending train runs in the northern part of the country because so many migrants are climbing aboard freight cars and getting hurt in the process.

Ferromex said it has temporarily ordered a halt to 60 trains carrying cargo that would fill 1,800 tractor trailers. It said some international trade would be affected by the stoppage. In recent days, there have been about a “half-dozen regrettable cases of injuries or deaths” among migrants hopping freight cars, the company said in a statement.