Armed men in northern Nigeria have kidnapped a group of foreign workers including one Briton, Sky sources have confirmed.
A picture purportedly showing the hostages kneeling on the ground in front of several masked men holding rifles was released to Nigerian media.
The armed men abducted the seven foreigners after attacking a construction company camp and killing a guard, police said.
"From the report we have received, the hostages are seven in all. They include four Lebanese, an Italian, a Briton and a Greek," Bauchi state police spokesman Hassan Auyo said.
This would make it the biggest kidnapping yet in a region that is under attack from Islamic extremists.
Greece, Lebanon and Italy have all said their citizens are involved. However, Britain's Foreign Office has not confirmed if a Briton is among them.
The kidnapping on Saturday night happened in Jama'are, a town in a rural portion of Bauchi state.
The gunmen attacked a local prison first, burning two police trucks, another Bauchi state police spokesman, Hassan Muhammed told the Associated Press.
Then they targeted a workers' camp for a construction company called Setraco, which is in the area building a road, Mr Muhammed said.
The gunmen shot dead a guard at the camp before kidnapping the foreign workers, he added.
A spokesman for the Foreign Office in Britain said: "We are aware of the reports and are making inquiries with local authorities."
Sky's Foreign Affairs Editor Tim Marshall said the Nigerian Islamist group that claimed responsibility for the kidnapping is a breakaway faction of the Boko Haram sect.
Known as Ansaru, the group is linked to al Qaeda and was blamed for a deadly attack on Nigerian troops travelling to Mali in 2012.
Nigeria's predominantly Muslim north has been under attack by Boko Haram in the last year and a half.
The country's weak central government has been unable to stop the group's bloody guerrilla campaign of shootings and bombings.
The sect is blamed for killing at least 729 people in 2012 alone, according to an AP count.
Foreigners have been frequently abducted by militant groups and criminal gangs for ransom in Nigeria's oil-rich southern delta and have become increasingly targeted in Nigeria's north as the violence has grown.
Sky News Special Correspondent Alex Crawford said: "Nigeria, particularly the north of Nigeria, has got a big problem. It's the scourge of the country and has been for many years now.
"Local Islamist groups called Boko Haram have been largely responsible for carrying out the kidnappings.
"This is one of the militant groups who have operating inside Mali. They are one of five extremist groups who are believed to have been running operations inside Mali and around the Sahel."
Gunmen who authorities say have links to Boko Haram also kidnapped an Italian and a British man last year in northern Kebbi State.
They were later killed during a rescue operation by Nigerian soldiers backed up by British special forces. The sect later denied taking part in that abduction.
Chinese construction workers have also been killed by gunmen around Maiduguri, the northeastern city in Nigeria where Boko Haram first began.
Setraco Nigeria, a construction and civil engineering company, is a subsidiary of Setraco International Holding group.
The Nigerian company, which was established in 1977, is currently working on expanding a major road in the north of the country.