Somali pirates kill four US hostages

US special forces have stormed the Quest, yacht hijacked by Somali pirates after four American hostages were shot dead, the US confirmed, the first Americans to be killed since hostage-taking by Somali pirates became rife.

The yacht's two owners, Jean and Scott Adam, from Los Angeles, had been sailing round the world distributing Bibles, accompanied by the two holidaymakers, Macay and Bob Riggle from Seattle.

According to the US military, a special forces team boarded the hijacked yacht - the Quest - on Tuesday after they heard shots fired and after the pirates launched a rocket-propelled grenade at a naval ship. One pirate was shot dead and another killed with a knife in hand-to-hand combat.

The bodies of two other pirates were found aboard, possibly the result of earlier fighting between the hostage-takers. Fifteen pirates have been arrested and are aboard the aircraft carrier USS Enterprise in all. They are almost certain to be taken to the US for trial.

The special forces provided immediate medical care to at least one of the hostages, Phyllis Macay, but she was too badly wounded to survive.

But Somali pirates in touch with news agencies claimed the four hostages were killed in retaliation after a pre-emptive strike by the US navy.

Two Somali pirates spoke with Reuters by telephone on Tuesday claiming the murders had been their response to a US attack. "Our colleagues called us this morning [saying] that they were being attacked by a US warship," said a pirate who identified himself as Muhammad.

"The US warship shot in the head two of my comrades who were on the deck of the yacht by the time they alerted us," he said. "This is the time we ordered the other comrades inside the yacht to react – kill the four Americans because there was no other alternative – then our line got cut."

"This is absolute nonsense. It is false," said a spokesman for US Central Command.

"We were in the process of talking with the pirates when we heard small arms fire and a rocket-propelled grenade was fired at the USS Sterett, a guided missile destroyer," he said. "It was only after that our special forces operations team went into action. The hostages were killed prior to any action by US forces."

The USS Sterett was close to the yacht at the time, only about 500 yards away, and the navy had been negotiating for the hostages' release.

The White House spokesman, Jay Carney, reportedly said Barack Obama had been woken in the middle of the night to be informed about the deaths. Obama had, on Saturday, authorised the use of force in the event of an imminent threat to the hostages.