20110223
reuters

WASHINGTON (Reuters) - Pirates shot dead four U.S. hostages on a private yacht on Tuesday, the deadliest incident involving Americans kidnapped for ransom in the increasingly dangerous waters off Somalia.

The U.S. military said the pirates shot the hostages before American special forces boarded the vessel.

U.S. troops killed two pirates as they took control of the the boat, and took 15 pirates into custody. Another two pirates were found dead when the U.S. special forces arrived but they were not killed by U.S. forces, the military said.

Secretary of State Hillary Clinton said the U.S. government was "deeply saddened and very upset by the murder of four American citizens" -- a "deplorable act" that underscored the need for more international cooperation against the pirates.

"We've got to have a more effective approach to maintaining security on the seas, in the ocean lanes, that are so essential to commerce and travel," she told reporters.

Pirate gangs preying on shipping lanes through the Gulf of Aden and the Indian Ocean typically target large merchant ships, with oil tankers the prize catch, but the snatching of foreigners can also yield high ransoms. There were around 750 pirate hostages at the end of January.

The Americans killed on Tuesday were Jean and Scott Adam, from California, as well as Phyllis Macay and Bob Riggle from Seattle.

The U.S. military said negotiations with the pirates had been under way when on Tuesday morning, without warning, a pirate fired a rocket-propelled grenade at the guided-missile destroyer USS Sterett.