* Briton, Italian, Greek, 4 Lebanese abducted Saturday
* Al Qaeda linked group behind other kidnappings in Nigeria
* Islamists top security threat to No.1 African oil producer (Adds Presidency comment, Ansaru quote, political background)
By Chukwuemeka Madu
KANO, Nigeria, Feb 18 (Reuters) - An Islamist group linked to al Qaeda claimed responsibility on Monday for kidnapping seven foreigners in an attack in a remote Nigerian town at the weekend, when raiders used explosives to blast their way into a housing compound in a hail of gunfire.
Gunmen killed a security guard and abducted a Briton, an Italian, a Greek and four Lebanese workers after storming the compound of Lebanese construction firm Setraco in Jama'are in Bauchi state late on Saturday.
It was the worst case of foreigners being kidnapped in the mostly Muslim north of Africa's most populous country since an insurgency by Islamist militants intensified two years ago.
"By Allah's grace (we) have the custody of seven persons, which include Lebanese and their European counterparts working with Setraco," read a statement from Ansaru, a group that has kidnapped other foreigners in Nigeria in the past.
The kidnapping was "based on the transgression and atrocities done to the religion of Allah by the European countries in many places such as Afghanistan and Mali," the statement said.
Three foreigners were killed in two failed rescue attempts last year after being kidnapped in northern Nigeria and Ansaru, blamed for those kidnaps, warned this could happen again.
"Any attempt or act (against us) by European nations or by the Nigerian Government will lead to (similar) happenings," said the group, which has not issued any specific demands.
Attacks by Islamist groups in northern Nigeria have become the biggest threat to stability in Africa's top oil producer. Western governments are concerned the Islamists may link up with groups elsewhere in the region, including al Qaeda's North African wing AQIM, especially given the conflict in nearby Mali.
France intervened in Mali last month as Islamist forces, which hijacked a rebellion by ethnic Touareg MNLA separatists to seize control of the north in the confusion following a military coup in March 2012, pushed south towards the capital Bamako.
In the Jama'are housing compound, walls were strewn with bullet holes and empty cartridges lay on the floor as police searched the deserted Setraco site on Monday, witnesses said. The remaining foreign workers abandoned their homes and fled to safer areas in Nigeria.
Islamist fighters first attacked a police station and a prison, burning vehicles to immobilise security officials, before striking the compound in a coordinated attack, the Setraco compound security manager said.
"Some of them attacked the camp from the north side, while others from the south. They blew holes in the security gates using explosives," Musa Alhamdu told Reuters.
"There was pandemonium after the gunmen opened fire on the four policemen attached to the camp, the policemen ran away as they were overpowered," Alhamdu added.
Ansaru's full name is Jama'atu Ansarul Musilimina Fi Biladis Sudan, which roughly translates as "Vanguards for the Protection of Muslims in Black Africa".
The group has risen to prominence only in recent months.
It claimed responsibility for a dawn raid on a major police station in the Nigerian capital last year, where it said hundreds of prisoners were released. Last month, it attacked a convoy of Nigerian troops en route to deployment in Mali.
The group said the abduction of the Frenchman last year, who is still missing, was motivated by France's ban of the full-face veil and its support for military action against Islamist insurgents in Mali.
Kidnapping of foreigners for ransom has been common in Nigeria's southern oil region for a decade but abductions by radical Islamists in the north only began two years ago.
Britain in November put Ansaru on its official "terrorist group" list, saying it was aligned with al Qaeda and was behind the kidnap of a Briton and an Italian killed last year during a failed rescue attempt.
A German engineer kidnapped in the northern city of Kano in January last year was killed by his captors in May when security forces made an attempt to rescue him.
Ansaru is thought to have loose ties to Boko Haram, a Nigerian Islamic militant group which has killed hundreds during a three-year-long insurgency focused mostly on the security forces, religious targets and politicians, rather than foreigners.
President Goodluck Jonathan has said several times in the last year that the military is winning the battle against what he calls "terrorism" in northern Nigeria.
Violence is stunting economic development in the north and risks increasing the divide with the wealthier and largely Christian south, which is home to the commercial hub Lagos and Jonathan's home oil-producing Niger Delta region.
The presidency said on Monday security agencies were taking all the necessary steps to rescue the kidnapped foreigners.
"The President condemns the kidnapping ... and reaffirms the Government's total commitment to stamping out all forms of terrorism and criminal abduction," a statement said. (Additional reporting by Isaak Abrak in Kaduna and Felix Onuah in Abuja; writing by Joe Brock; editing by Giles Elgood)