Above: The police have been accused of heavy-handed tactics
Student leaders in Chile are calling on fellow pupils to join a one-day national strike over their demands for an overhaul of educational reform.
Students were continuing sit-ins at schools across Chile, while others were gathering for marches and rallies.
Talks with the government last Friday failed to break the deadlock and end the biggest student protest in years.
The government has offered extra school funding but says it cannot give free bus passes to all - a key demand.
There were no reports of violence as the day of protest began, but police in the capital, Santiago, said tyres were burnt in several places.
The authorities have said they hope any demonstrations will pass off peacefully but have warned that the police will step in to deter any violence.
Chile last week saw its biggest student protests in decades as more than 500,000 pupils demonstrated.
There were ugly scenes last Tuesday when riot police clashed with some of the students and several hundred people were arrested.
Television footage of young people being beaten by the security forces brought an outraged reaction from many parents and subsequently led President Michelle Bachelet to fire the head of the riot police.
The students demands include a complete overhaul of an education system they say is under-resourced and leads to huge disparities between public and private schools.
They want a university entrance exam fee to be waived and free public transport.
President Bachelet, who took office in March and is facing her biggest political test so far, has offered free passes and a waiver of exam fees for the poorest students.
But this has so far not been enough for the students to call off their protests.
On Monday, more than 2,000 students marched through the city of Valparaiso, while in Santiago many students were holding what they termed a "day of reflection" in their schools, which they have barricaded with chairs and desks.
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