Water cannons, tear gas and police truncheons were used to break up a student demonstration in Santiago on Wednesday.
Several protesters were detained by police, who were under orders to prevent the protest from using the Alameda, which runs through the heart of the capital.
The protesters, mostly secondary school students, were calling for an end of sexual abuse in educational facilities and non-sexist sex education.
Some marchers also expressed anger over new guidelines issued by the Chilean Health Ministry limiting access to abortion in the country.
Current President Sebastian Pinera’s first government in 2010-2014 was put under severe political pressure by a student movement demanding educational reform.