 According to the testimony of Ahn Myong-chol, a guard at a similar camp, and Mun Hyon-il, a nearby resident, the riot started when one political prisoner at the camp killed a guard in protest; he was then joined by 200 others at the scene who overcame another guard.At the height of the riot, some 5,000 prisoners were openly in revolt.Reinforced from a second camp, guards proceeded to open fire on the rioters with machine guns, the defectors have stated.