Riots erupted on the streets of the Chilean capital Santiago after talks between student leaders and the government broke down.
Security forces used water cannon and tear gas to break up gangs of protesters. Students responded with rocks and other missiles.
Over 130 people were arrested and at least 30 people injured in the latest clashes on Thursday. Those hurt included police, protesters and a journalist.
The demonstration kicked off after five hours of talks with the Education Minister Felipe Bulnes stalled over disagreement on how to cut education costs and work towards a free education system, a key demand of the students. They say high costs make further education inaccessible and leave students with massive debts.
Students have been protesting almost daily since June.