KANO, Nigeria (AP) - Radical Islamic fighters killed seven foreign hostages in Nigeria, European diplomats said Sunday, making it the worst such kidnapping violence in decades for a country beset by extremist guerrilla attacks.
Nigeria's police, military, domestic spy service and presidency remained silent over the killings of the construction company workers, kidnapped Feb. 16 from northern Bauchi state. The government's silence only led to more questions about the nation's continued inability to halt attacks that have seen hundreds killed in shootings, church bombings and an attack on the United Nations.
The latest victims were four Lebanese and one citizen apiece from Britain, Greece and Italy.
Britain and Italy said all seven of those taken from the Setrapo construction company compound had died at the hands of Ansaru, a previously little-known splinter group of the Islamic sect Boko Haram. Greece also confirmed one of its citizens was killed, while Lebanese authorities didn't comment.
"It's an atrocious act of terrorism, against which the Italian government expresses its firmest condemnation, and which has no explanation, if not that of barbarous and blind violence," a statement from Italy's foreign ministry read.
Italy also flatly denied a claim by Ansaru that the hostages were killed before or during a military operation by Nigerian and British forces, saying there was "no military intervention aimed at freeing the hostages."
Italian Premier Mario Monti identified the slain Italian hostage as Silvano Trevisan and promised Rome would use "every effort" to stop the killers. British Foreign Secretary William Hague called the killings "an act of cold-blooded murder" and identified the U.K. victim as Brendan Vaughan.
Greece's foreign ministry said authorities had already informed the hostage's family.
Ansaru issued a short statement Saturday saying its fighters kidnapped the foreigners from the construction company's camp at Jama'are, a town about 125 miles north of Bauchi, the capital of Bauchi state. In the attack, gunmen first assaulted a local prison and burned police trucks, authorities said. Then the attackers blew up a back fence at the construction company's compound and took over, killing a guard in the process.
The gunmen appeared to be organized and knew who they wanted to target, leaving the Nigerian household staff, while quickly abducting the foreigners.
Ansaru said it killed the hostages in part because of local Nigerian journalists reporting on the arrival of British military aircraft to Bauchi. However, Ansaru's statement cited local news articles that instead said the airplanes were spotted at the international airport in Abuja, about 180 miles southwest.
The U.K. Defense Ministry said Sunday the planes it flew to Abuja ferried Nigerian troops and equipment to Bamako, Mali. Nigerian soldiers have been sent to Mali to help French forces and Malian troops battle Islamic extremists there. The British military said it also transported Ghanaian soldiers to Mali the same way.
The ministry declined to comment further. Ansaru had said it believed the planes were part of a Nigerian and British rescue mission for the abducted hostages.
The U.K. has offered military support in the past in Nigeria to free hostages. In March 2012, its special forces backed a failed Nigerian military raid to free Christopher McManus, who had been abducted months earlier with Italian Franco Lamolinara from a home in Kebbi state. Both hostages were killed in that rescue attempt.
"I am grateful to the Nigerian government for their unstinting help and cooperation," Hague said in a statement, without addressing the claim that the U.K. had launched a rescue effort.
In its statement Saturday, Ansaru also blamed the killings on a pledge by Nigerian President Goodluck Jonathan to do "everything possible" to free the hostages. Presidential spokesman Reuben Abati didn't respond to requests for comment Sunday.