The latest march by students demanding free education in Chile has turned ugly, with clashes between protesters and police.
Rallies have often turned violent since the movement started more than a year ago.
Security forces used water cannons and tear gas to disperse the crowd in the capital, Santiago.
The confrontation came during an unauthorised demonstration, demanding changes to Chile’s largely privatised education system.
Hooded youths regularly mix with peaceful demonstrators at the protests. Rocks were thrown at police. Reports said three buses were set alight.
Education reforms proposed by Chile’s President Sebastian Pinera are not enough, students say. They are also angry at a proposed public order crackdown.