Mexican authorities stopped three freight trucks which carried a total of 77 undocumented migrants, mostly Central Americans, dpa quoted the Security Ministry of the southern Mexican state of Chiapas as saying Saturday. The trucks were found, following an anonymous tip-off, near the village of Plan de Ayala, in the municipality of Tuxtla Gutierrez. Of the 77 migrants, 23 are Guatemalan, 27 are from El Salvador, 24 from Honduras and three are from China. They were squashed together and needed immediate medical assistance and food. The alleged human traffickers in charge managed to escape after firing their weapons into the air.