Thousands of migrants in Mexico have been clambering onto dangerous freight trains rumbling northward in a scramble to reach the U.S. border by the time the United States ends a tough migration policy later this week.
In recent weeks, up to several hundred people have boarded daily, activists and officials say, with many setting off atop train cars pulling out from a brief stopping point at a garbage dump in Huehuetoca, a town north of Mexico City.
