
Around fifteen thousand students marched through the city wearing red carnations to protest the military occupation of the university before gathering at the Plaza. As the sun set the military and armed police surrounded the square and opened fire on both demonstrators and bystanders. The indiscriminate killing continued through the night, with nearby residences also subject to attack in house-to-house raids.

Between two- and three-hundred men, women and children died that night at the hands of the authorities. Witnesses claimed that the bodies were later removed in garbage trucks. The government explanation for the massacre was that armed demonstrators had fired down on the police and army from the surrounding buildings first, and that their forces responded in self-defence.
The National Security Archives pages on the George Washington University site include a number of articles about the massacre as well as the text of related document.
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