British construction workers may have been among seven kidnapped by gunmen in Nigeria, after a gang killed a guard at a site in Bauchi state on Saturday night.
A Foreign Office spokeswoman said: "We are aware of the reports and are making inquiries with local authorities."
Local government chairman Adamu Aliyu told the Associated Press that those kidnapped were from Britain, Italy, Greece and Lebanon.
Radical Islamist group Boko Haram has been engaged in a guerilla campaign in the largely Muslim north of Nigeria over the past 18 months.
Foreigners have long been targeted by criminal gangs in the oil-rich south of the country, abducted usual for hefty ransoms, but foreigners are now being targeted in the north of the country, and some Chinese workers were recently killed in Maiduguri in the north east, as the conflict escalates.
Last month around 40 hostages, six understood to have been Britons, were killed in an attack on the In Amenas gas field in Algeria.
Some 29 of the hostage-takers died, while three were captured by Algerian troops during a special forces mission to end the four-day stand-off which began on January 16.
In the wake of the crisis, Prime Minister David Cameron pledged to put terrorism "right at the top of the agenda" for Britain's presidency of the G8 nations this year and vowed to show "iron resolve" in tackling Islamist threats.