At least 30 people were killed when Iraqi forces foiled a prison break staged by a group of over of 150 detainees held on terrorism charges in Diyala province, a security source said on Saturday.The attempt started when the group of detainees took the gun of a guard during his tour late Friday night in a jail in Khalis city, the source told Xinhua news agency.The inmates later seized more departments of the jail, gained more weapons, and clashed with the security forces for more than four hours after reinforcement troops arrived at the scene and regained control of the situation at dawn, the source said.Twenty detainees and 10 police officers were killed and 15 more policemen were wounded, the source said, adding that some of the 150 detainees escaped from the jail but there is no immediate report about their number.