Many migrants from Central America board the train in the hope of a new life in the US, but hundreds of them never make it through Mexico.

In the most recent case, a group of at least forty passengers were tied up and "disappeared".

Central American authorities have long urged Mexico to ramp up security along these human smuggling routes.

Now Honduras, Guatemala and Salvador are demanding that Mexican authorities investigate last week's abductions.

Al Jazeera's Monica Villamizar reports.