Two Europeans held hostage in Nigeria by kidnappers claiming ties to al-Qaeda were killed before rescuers could free them, authorities said on Thursday, March 8, AP reported.

The men - a Briton and an Italian - were killed by their captors. A Nigerian official said the two died in the crossfire during the rescue attempt, Prime Minister David Cameron said.

Chris McManus and Franco Lamolinara were taken captive in May. The pair had been working on a bank construction project in Nigeria, a country that has seen a rise in violence linked to the Islamist extremist group Boko Haram.

A number of foreigners have been kidnapped while working in Nigeria in recent years - including many who worked in the oil industry. But the kidnapping of McManus and Lamolinara in northwest Nigeria was highly unusual for that region of the country, an arid land that approaches the Sahara Desert and Nigeria's border with neighbouring Niger.

Boko Haram, which means "Western education is sacrilege" in the Hausa language of Nigeria's Muslim north, has been waging an increasingly bloody fight against the nation's weak central government.

Western diplomats and analysts say Boko Haram has had contacts with two other al-Qaeda-influenced terror groups in Africa. However, they say the sect has splintered, with one wing now willing to use extreme violence. The sect also has begun targeting schools and Christians in Nigeria, a multiethnic nation of more than 160 million people.