The killing of student and civilian protesters as well as bystanders by Mexican government employees in the Plaza de las Tres Culturas in the Tlatelolco section of Mexico City. The violence occurred ten days before the 1968 Summer Olympics celebrations in Mexico City. While at the time, government propaganda and the mainstream media in Mexico claimed that government forces had been provoked by protesters shooting at them, government documents that have been made public since 2000 suggest that the snipers had in fact been employed by the government.