Gunmen attacked a camp for a construction company in rural northern Nigeria, killing a guard and kidnapping seven foreign workers from Britain, Greece, Italy and Lebanon, authorities said Sunday, in the biggest kidnapping yet in a region under attack by extremists. The attack Saturday night happened in Jama're, a town in a rural portion of Bauchi state. There, the gunmen first attacked a local prison, burning two police trucks, Bauchi state police spokesman Hassan Muhammed told The Associated Press. The gunmen then targeted a worker's camp for a construction company called Setraco, which is in the area building a road, Muhammed said. The gunmen shot dead a guard at the camp before kidnapping the foreign workers, the spokesman said. Adamu Aliyu, the chairman of the local government area that encompasses Jama're, identified those kidnapped as one British citizen, one Greek, one Italian and four Lebanese. Britain's Foreign Office said Sunday it was looking into reports that a U.K. national had been kidnapped in Bauchi state.