Students and authorities have clashed in Santiago, Chile after thousands of activists marched in a prolonged battle over education reform.

Massive numbers showed up for the strike called by teachers' groups and student organisations.

The march remained peaceful early on until a group of hooded students threw rocks at riot police who retaliated with water cannon and tear gas.

Students dragged objects into the streets, setting fires to slow down police while officers continued firing water and tear gas until the protesters were dispersed.

In Chile, tuition fees are among the world's highest, and students have demanded action from Sebastian Pinera's government.