On July 26, 1968, demonstrators attempted to gather at the Zócalo, which was reserved for organized demonstrations of support for the president. As more and more people gathered, Díaz Ordaz "regarded the movement as an affront to the dignity of Mexico".). The PRI had no control over student demands for respect and constitutional rights. By August 13, 1968, "100,000 people were protesting against the regime’s disrespect for public liberties and the presence of tanks in the city streets". The government saw the growing political unrest as "a revolutionary conspiracy...designed to bring down the existing political order". People gathered on the evening of October 2, 1968, at the Plaza de las Tres Culturas (Plaza of Three Cultures). The administration made no attempt to establish dialogue. Troops and police opened fire on the Tlatelolco demonstrators and massacred them.