This article is more than 9 years old

This article is more than 9 years old

Four Americans taken from their yacht in the Indian Ocean by Somali pirates have been shot dead, the US military has said.

US naval forces on the way to try to rescue the Americans heard gunshots and on arrival found the four hostages had been killed.

Two pirates were killed and 15 detained during the incident, which took place on Monday.

The remains of two other pirates, who had been dead for some time, were found. The US military did not state how those two died. In total the US said 19 pirates were involved in the hijacking of the American's yacht, the Quest.

The deaths mark the first time US citizens have been killed in pirate attacks, which have plagued the Gulf of Aden and the Indian Ocean for years.

The Quest was the home of Jean and Scott Adam, a couple from California who had been sailing around the world since December 2004. The two other Americans on board were Phyllis Macay and Bob Riggle, of Seattle, Washington.

Rear Admiral Charles Gaouette, deputy commander of the US navy's fifth fleet, said those on board were part of a group that had set sail from the southern tip of India. The vessel had apparently been bound for Oman.

The Adams's website documents their worldwide voyage. It includes trips to New Zealand, China, Cambodia and Panama.

The crew had joined a group of other yachts for the leg across the Indian Ocean for safety reasons.

Hostages are normally taken to Somalia and then ransom negotiations begin. The US navy had hoped to intercept the pirates and prevent them reaching the coast.

The US central command said that negotiations were under way with the pirates when the US forces heard gunfire, boarded the yacht and found the four American bodies.

"As they responded to the gunfire, reaching and boarding the Quest, the forces discovered all four hostages had been shot by their captors," General James Mattis said in a statement.

"We express our deepest condolences for the innocent lives callously lost aboard the Quest," the statement added.

The military said US forces have been monitoring the Quest for about three days, since shortly after the pirate attack on Friday. Four navy warships were involved, including an aircraft carrier.

Two years ago, the US navy intercepted pirates who had attacked a US cargo ship, the Maersk Alabama, and rescued the captain, killing three pirates and arresting another.

Last week a Somali pirate was sentenced to 33 years in prison by a New York court for the 2009 hijacking of that vessel. That hijacking ended when US navy sharpshooters killed two pirates holding the ship's captain.