Police in Mexico have raided three teachers' colleges in the western state of Michoacan after more than a week of protests against curriculum changes.
Officers arrested at least 120 people as they stormed the schools, where students were holding buses and delivery trucks that they had seized.
Ten officers were injured, three of them seriously, in clashes with demonstrators, state officials said.
Several vehicles including patrol cars were set on fire in Monday's violence.
The standoff at the colleges began earlier this month, when students took control of the campuses in protest at plans to require them to take courses in English and computer science.
They say basic skills are more of a priority in the rural areas they will be working in.
The protesters have seized dozens of passing vehicles and held many of the drivers.
The government says the hijackings lose the country huge sums of money.
Monday's early morning raids came a day before a visit by Mexico's outgoing president, Felipe Calderon, to towns in Michoacan - including Cheran, the site of one of the schools involved in the protest.
Mexican police reportedly received back-up from US-supplied Black Hawk helicopters, fire engines and ambulances.
State interior minister Jesus Reyna Garcia said 120 students were taken into custody - but unofficial accounts put the figure at more than 300.
Michoacan state spokesperson Elina Ambriz said one campus - in the city of Arteaga - had been recovered without resistance.
The raids were the latest in a round of crackdowns against college occupations.
Last month, students who had been rejected from the University of Michoacan took over the campus, demanding admission.
And a long-running dispute about low grades at Mexico City's Autonomous University has seen tensions grow between protesters and other students locked out of classrooms.