Chilean government and student representatives met for talks on education reform after a day of fierce clashes between student protesters and police in the capital.
Riot police used tear gas and water cannon to disperse tens of thousands of protesters, some of whom attacked security forces with sticks and rocks, in the latest unrest following months of massive demonstrations.
Tear gas wafted into area homes and office buildings, briefly causing panic among residents around a park where the clashes occurred.
The demonstration had begun peacefully in front of the University of Santiago, but turned violent near a park outside an area that authorities had approved for the march.
Organizers estimated the crowd at 90,000, saying participants included university students, secondary school students and teachers. The police gave no estimate for the number of demonstrators.
The protest was held just hours before talks between students representatives and Education Minister Felipe Bulnes.
In the talks the students presented their main demands, including free public education, before both sides agreed to meet again next week. Bulnes was unable to convince the students to return to class in the meantime.
"Free education ... is the main topic we will discuss at the next meeting," said student leader Camila Vallejo after the talks.
Bulnes said he was satisfied with the first meeting, but hoped the students would return to class as a "gesture."
Classes have been on hold in many schools and universities during the long-running demonstrations, which routinely draw tens of thousands of students into the streets, representing the largest protest movement in Chile since General Augusto Pinochet's military dictatorship ended in 1990.
Chile's main student federation on Tuesday agreed to discuss education reform with the government of President Sebastian Pinera -- the first rightwing leader since Pinochet -- after nearly five months of demonstrations.
But student leaders said no classes would be held while the talks are ongoing, in order to maintain pressure on the government.
Vallejo denounced the police's handling of the latest protest, saying: "Police should have cooperated to control the protest, but not suppress it."