A march here Wednesday by high school students demanding improvements to Chile's underfunded public education system ended with three buses set ablaze and dozens arrested.
The protest was convened by the ACES high school students association, with support from the groups that represent Chile's collegians.
Demonstrations also took place in the seaside resort of Viña del Mar, where 11 people were arrested and a pharmacy and supermarket destroyed, the northern town of La Serena and the southern city of Valdivia.
The Santiago regional government refused to issue ACES a permit to march on the city's main thoroughfare, the Alameda, but the students rejected the two alternative routes proposed by authorities.
Determined to protest on the Alameda, some 5,000 students - according to Santiago Mayor Pablo Zalaquett - gathered at 10:00 a.m. in Plaza Italia square, occupying the sidewalks and forcing traffic to a crawl.
As soon as the students began to move toward the Alameda, Efe saw them met by tear gas, water cannon and truncheon-wielding mounted police.
The protesters responded by hurling rocks and other projectiles as the cops, vandalizing public property and trying to erect barricades on the surrounding streets.
Some in the crowd also destroyed private vehicles and damaged an insurance company office and an auto dealership.
Three public buses were burned and witnesses said hooded militants had previously ordered the passengers off the vehicles.
The students, however, said the buses were traveling empty and accused authorities of staging a set-up.
The disturbances went on for at least five hours, resulting in dozens of arrests and leaving six police injured, official sources told Efe.
Wednesday's events "have nothing to do with the problems of education," government spokesman Andres Chadwick told reporters, insisting that "no one is above the law" or can claim "the right to convene illegal marches."
"Minister Chadwick, we don't feel we are above the law. Those who have been above the law are those who have profited at the cost of our dreams," the leader of the University of Chile student organization, Gabriel Boric, replied on Twitter.
Chilean student took to the streets in large numbers more than 40 times in 2011 to denounce a highly stratified education system that funnels state subsidies to private institutions even as public schools in poor areas struggle.
Chile's public schools and universities were neglected by the 1973-1990 dictatorship of the late Gen. Augusto Pinochet, who embraced doctrinaire free market policies.
Private schools mushroomed under the military regime and the trend continued after democracy was restored, even during the 1990-2010 tenure of the center-left Concertacion coalition.
President Sebastian Piñera, a right-wing billionaire who thrived during the Pinochet era, has taken some steps to make college more affordable for low-income students and is now asking Congress to pass a tax reform bill that would generate as much as $1 billion in additional education funding.
Critics dismiss that figure as woefully inadequate.
"The tax burden today is 20 percent of GDP in total. Now there's a violent fight about whether it grows from 20 percent to 20.3 percent," the president of the Education 2020 Foundation, Mario Waissbluth, told Efe. EFE