More than 300 students, many wearing masks, descended on the Guerrero government headquarters in Chilpancingo, threw rocks at its windows and burned around 10 vehicles, including trucks and a federal police vehicle.
"We are asking the same thing as usual. We want to see our comrades alive," a masked student told AFP yesterday.
The case has repulsed Mexico since gang-linked police attacked busloads of students in the Guerrero city of Iguala on September 26, in a night of violence that left six people dead and the 43 missing.
But parents of the missing and fellow students at their teacher-training college near Chilpancingo refuse to believe the authorities until they get DNA results from independent Argentine forensic experts.