An armed commando raided a prison in the northern Mexican city of Torreon, beating up and burning to death three inmates, the authorities said Tuesday according to dpa. The incident happened late Monday, when several people arrived in four vans, overpowered the guards and hit the three inmates before pouring petrol on their bodies and setting them on fire, the Coahuila state police said. Unofficial reports said the commando took away six to eight inmates, although state authorities did not confirm this.