A car bomb explosion outside a church, near the Nigerian city of Bauchi. Although Boko Haram did not claim responsibility, the militant Islamist group Boko Haram regularly targets churches
A car bomb explosion outside a church, near the Nigerian city of Bauchi. Although Boko Haram did not claim responsibility, the militant Islamist group regularly targets churches

Gunmen in northern Nigeria have attacked a camp belonging to a construction company, killing a guard and kidnapping seven foreign workers from Britain, Greece, Italy and Lebanon.

The raid, which resulted in the biggest kidnapping so far in a region under attack by Islamic extremists, happened on Saturday night in a rural part of Bauchi state.

Before the raid, there was an attack on the local police station and prison, where two police trucks were blown up, in the town of Jama'are, some 125 miles (200km) north of the state capital, Bauchi.

Next, they targeted a workers' camp for the Lebanese construction company Setraco, which is building a road, said Bauchi state police spokesman Hassan Muhammed. The gunmen shot dead a security guard before kidnapping the foreign workers, he added.

Adamu Aliyu, the chairman of the local government, identified those kidnapped as one British citizen, one Greek, one Italian and four Lebanese.

Britain's Foreign Office said it was looking into reports that a UK national had been siezed.

The state capital has itself been attacked several times by Boko Haram. The Islamic sect believes politics in northern Nigeria have been seized by a group of corrupt, false Muslims.

It wants to wage war against them, and the Federal Republic of Nigeria generally, to create a "pure" Islamic state ruled by sharia law.

Earlier this month, nine polio vaccinators were shot dead at two health centres in northern Nigeria.

Some Nigerian Muslim leaders have previously opposed polio vaccinations, claiming they cause infertility.

The BBC's security correspondent Gordon Corera says Boko Haram has emerged as one of the most prolific militant groups in West Africa, carrying out a large number of low-level attacks but also some more sophisticated attacks.

The sect is blamed for killing at least 729 people in 2012 alone, according to Associated Press.

Gunmen who authorities say have links to Boko Haram also kidnapped an Italian and a British man last year in northern Kebbi state. The gunmen were later killed during a rescue operation by Nigerian soldiers backed up by British special forces. The sect later denied taking part in the abduction.

Commercial activities in the northern trade hub of Kano are down 50 percent since 2010 because of the violence waged by Boko Haram, and government efforts to curb it, says the Kano traders' union.

"The north is losing heavily due to the violence. When you destabilise Kano, which is the commercial nerve centre of the north, you are threatening the socioeconomic well-being of the north," Nigeria's Information Minister Labaran Maku told reporters.

So far, no one has claimed responsibility for the attack.