Mexico City police use tear gas in clash in Zocalo Square

Thousands of riot police charge at teachers who have lived in a 'tent city' in Zocalo Square for many weeks

Mexican Federal Police are pictured in the surroundings of Mexico City's Zocalo square during clashes with teachers protesting against an education reform on 13 September as clashes continued today (AFP/Getty Images)

Riot police in Mexico City have used tear gas and water cannons to disperse teachers protesting against educational reform.

Violent clashes occurred minutes after a deadline set by the Mexican government for protesters to leave Zocalo Square, where thousands have lived in a large protest camp for many weeks.

Riot police armed with batons and shields charged at the teachers who had remained past the deadline, as helicopters circled overhead.

Officers were met with missiles from a hardcore of protesters barricading themselves into the square.

The protesters were overwhelmed by thousands of police and were accused of using heavy-handed tactics to clear the camp.

"With a lot of viciousness, they grabbed me and [put me] on the ground, holding my feet. They caused injury on my septum and hit my body," one teacher told Sky News.

It is believed water cannons were used mainly to put out fires started by the protesters and clear rubbish from the improvised 'tent city'.

The encamped teachers were protesting against President Enrique Pena Nieto's educational reforms that included performance-related tests for teachers.

Last week, thousands of members of the country's teachers' union - which critics argue is corrupt and holds too much power - demonstrated outside the Senate as the bill was being passed.

Sunday 15 September is Mexican Independence Day and authorities were keen to clear the square, one of the capital's best-known landmarks by then. However, commentators have pointed out that the image of riot police does not present the sense of unity that President Nieto would have hoped for on his first Independence Day as leader.