Tripoli. Salahuddin District. 27th August 2011.\nA survivor who lost his brother when at least 55 men were executed late on Tuesday in Tripoli's Salahuddin district by militiamen loyal to Colonel Gadaffi. Here he is helped from the scene after seeing the charred remains of his brother, identifying him from the position of the corpse. \nThe massacre occured in a yard used to store farm machinery in the Salahuddin district of Tripoli, adjacent to the capitals largest military base. The prisoners-suspected of suporting the rebels were herded into a barn adjacent to Tripoli's largest military headquarters, where they were machine gunned. Hand grenades were thrown at survivors before the bodies were set alight. This is one of the worst single atrocities documented so far during Libya's revolution and survivors place Col. Gadaffi's son Khamis at the scene giving orders shortly before the exections began. At least 7 men escaped the killings, but the bodies of up to 90 others, also believed to have been killed there, are still missing. Mounds of bulldozed earth in the yard suggest the presence of a mass grave. Gadaffi's troops fled the scene on Friday evening as rebels advanced through the area. The photographer and writer were escorted to the location by locals doctors and fighters on Saturday morning.