Police used water cannons and tear gas to break up a march by thousands of Chilean students on Thursday, the first protest this year by student groups whose demonstrations demanding education reform paralyzed major cities in 2011.
Police said about 50 protesters were detained in Thursday's march on Santiago's main avenue, which drew roughly 2,000 participants. Organizers said 5,000 to 7,000 high school students took part along with some university students.
Police broke up the march when a few hundred students crossed a police barrier and tried to march to the education ministry. The streams of water knocked over some protesters and others dodged tear gas canisters.
"The government is giving us a clear signal that it is intransigent, but we are strong, we know that we are strong, and the government is afraid of us," said student leader Maximiliano Salas.
Police in Chile's capital said the march wasn't authorized by municipal authorities because the students didn't apply for permission 48 hours in advance.
Police detained a cameraman for Colombia's NTN 24 station for allegedly "blocking and impeding" the officers, according to Chile's Foreign Press Association.
The mobilization was called by the Coordinating Assembly of High School Students to demand free quality education and protest the expulsion of about 200 students who joined last year's protests. Some university students also joined them.
The crisis over education reform in Chile remains unresolved despite seven months of mass demonstrations last year by students, teachers and families. The marches have generally been peaceful but often end with clashes between police and a minority of hooded activists throwing stones and molotov cocktails.
Now that summer vacations are over in Chile, both sides expect many more clashes to come.