Seven foreign hostages kidnapped last month by a Nigerian Islamist group from a construction firm’s compound have been killed, the Italian and Greek Foreign Ministries said yesterday.

Al Qaeda-affiliated group Ansaru said on Saturday it had killed the hostages seized on February 7 in the northern state of Bauchi because of attempts by Nigerian and British forces to free them.

It published grainy photos purporting to show the bodies of a Briton, an Italian, a Greek and four Lebanese workers snatched from the Lebanese firm Setraco.

Foreign governments had not been able to confirm the killings until Sunday. Italy and Greece denied any attempt to rescue them had been made by any of the governments involved. Nigeria had no confirmation of the killings.

“Our checks conducted in co-ordination with the other countries concerned lead us to believe that the news of the killing of the hostages seized last month is true,” an Italian Foreign Ministry statement said.

Security has become a top concern for oil and infrastructure companies across the region after gunmen loyal to al-Qaeda’s north African franchise stormed an Algerian gas plant in January killing 37.

Ansaru was suspected of being behind the killing of a British and Italian hostage a year ago in northwest Nigeria during a botched attempt to rescue them by British and Nigerian forces. Britain has labelled it a terrorist organisation.

It also claimed responsibility for the kidnapping in December of a French national, still missing.

Nigerian authorities are still looking for a French family of seven kidnapped in Cameroon and moved over the border by militants who said they were from Boko Haram.