Mexico teachers clash with police in Zocalo Square

Police in Mexico City have clashed with protesters during an operation to clear a square occupied by striking teachers.

Riot police, backed up by tanks and helicopters, broke through the barricades set up by the teachers shortly after a deadline for them to disperse passed.

Some demonstrators responded with petrol bombs.

The teachers have been demanding changes to education reforms approved by President Enrique Pena Nieto.

Will Grant reports.