Striking teachers cleared from Mexico City square Federal police have swept thousands of striking teachers out of the heart of Mexico City. They used tear gas, flash grenades and water cannon to bring a swift end to the protest, which has lasted for weeks. The demonstrators have been occupying Zocalo square, to express their anger over reforms to the national education system. The structural changes include a reduction in union control over the hiring and assignment of teachers. The protesters have marched through the capital more than a dozen times during the last two months. The government had set an afternoon deadline for them to leave and police moved in when that was ignored. More than 20 demonstrators were arrested. Authorities did not immediately report any injuries. More about: Education, Mexico, Police violence, Student