NAIROBI, Kenya - The United States government says it is assessing possible responses after Somali pirates hijacked a yacht with four Americans on board in the Arabian Sea off the coast of Somalia.

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Pirates hijacked the yacht Quest on Friday, two days after a Somali pirate was sentenced to 33 years in prison by a New York court for the 2009 hijacking of the Maersk Alabama.

The Quest is the home of Jean and Scott Adam, a couple who has been sailing around the world since December 2004, according to a website the Adams keep.

Matt Goshko, a spokesman at the US Embassy in Kenya, said Saturday that all relevant US agencies are monitoring the situation and are assessing options and possible responses.