LONDON - Foreign Secretary William Hague said on Sunday that a Briton held hostage in Nigeria was “likely to have been killed at the hands of his captors” along with six other foreigners. He condemned the deaths, claimed by a militant group on Saturday, as “an act of cold-blooded murder” and said Britain would work with the Nigerian government to hold those responsible to account. “It is with deep sadness that I must confirm that a British construction worker, held hostage in Nigeria since 16 February, is likely to have been killed at the hands of his captors, along with six other foreign nationals who we believe were also tragically murdered,” Hague said in a statement. “This was an act of cold-blooded murder, which I condemn in the strongest terms.” Hague named the British man as construction worker Brendan Vaughan. He offered his condolences to the families of those killed, adding: “Responsibility for this tragic outcome rests squarely with the terrorists. I am grateful to the Nigerian government for their unstinting help and cooperation. We are utterly determined to work with them to hold the perpetrators of this heinous act to account, and to combat the terrorism which so blights the lives of people in Northern Nigeria and in the wider region.” Nigerian group Ansaru on Saturday claimed to have killed seven foreign hostages abducted from a construction site last month in the country’s restive north.