Other witnesses testified that on the fateful day prison officials ordered the approximately 1,000 prisoners to line up in the prison yard. After a few minutes, they were fired upon from the prison walls and guard towers with machine guns and grenades, killing at least seventy people.[3][1] Another number is 67.[11] Over the next twenty-four hours, prison guards, special police, and possibly paramilitaries attacked prisoners who were hiding in the prison's buildings, basements, and sewers, killing at least another twelve inmates.[3]