If security forces were firing tear gas or another device at the compound, that can explain why the blaze spread quickly.Here is that video:Special Police anti-riot forces heading to Evin at around 22:oo local timeFars new agency also affiliated with the Revolutionary Guard confirmed after 22:00 local time that "a riot" took place in the prison by "common criminals" who got into an skirmish with guards and set the clothing depot of the prison on fire.People around the prison said special riot police have been firing tear gas both inside the prison at inmates who broken out of the buildings and also the crowd gathered outside.One emergency worker at the scene told the official government news agency IRNA that no one had died but there were at least eight people injured.However, with multiple sounds of explosions and a huge blaze, it is hard to believe that an emergency crew member would have full information at this stage."