Four people were killed and 10 others injured Sunday when inmates in a prison in northern Afghanistan attacked police officers, dpa cited officials as saying. The violence occurred as officers at the jail in Jowzjan province were searching for knives and other contraband items, provincial police chief Faqir Mohammad Jauzjani said. Prisoners attacked three officers inside a jail cell, Jauzjani said. 'They killed all the three officers, either by knives they had or using the officers' guns,' he said, adding that other prisoners also started to riot and attacked the guard towers. One prisoner was killed and 10 others injured in the ensuing fighting, Jauzjani said. 'The rioters were the Taliban fighters. And I think it was a jailbreak conspiracy,' said Jauzjani.