Ten Iraqi policemen and eight prisoners were killed late on Friday as dozens of inmates escaped from a prison holding 300 people charged with acts of terrorism, a security official and a police source said on Saturday. It was not clear if any high-profile prisoners were held in the prison in Al-Khalis, about 80 km (50 miles) northeast of Baghdad, Diyala Province's security committee leader, Seyyid Sadiq al-Husseini, said. "The inmates started fighting among themselves which drew the attention of the police guards who went to break up the fight," the police source, who asked not to be named, said. "Then the prisoners attacked them, stripped them of their weapons and started a riot while also managing to capture the armory of the prison." Iraq's government faces multiple security challenges, including from Islamic State militants who have seized large parts of the north and west, and widespread sectarian violence. Authorities declared a curfew in Al-Khalis and raided houses in search of escaped convicts, said a police source. A car bomb in the capital, meanwhile, killed seven civilians and wounded 14 others, police and medical sources said, reminding the government of lingering security threats since the last U.S. soldiers pulled out of Iraq in 2011, ending nearly nine years of war that cost tens of thousands of Iraqi and almost 4,500 American lives.