Santiago - Tens of thousands of students and teachers have filled the streets of Chile's capital, demanding more government investment in public education.
The march was one of the biggest protests against centre-right President Sebastian Pinera since he took office last year.
Police estimate 50 000 people attended the march, while organisers put the number at double that.
The protesters are demanding that Chile's government assume a bigger role in the country's educational system and oppose the growth of private schools. Smaller groups splintered off from the main march and confronted police, who responded with teargas and water cannons.
Middle-school students launched similar marches in 2006 against then-President Michelle Bachelet. - Sapa-AP