BAUCHI, Nigeria — 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 Islamic 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.