A U.S. ship operator says the American crew of a hijacked vessel off the coast of Somalia has retaken control of the ship, but says one crew member is still being held hostage by pirates.

Maersk Line says the crew on the ship are safe and no injuries have been reported.

The 17,000-ton container vessel "Maersk Alabama" was seized by pirates early Wednesday off the coast of Somalia's northern Puntland region, about 450 kilometers southeast of the town of Eyl. The crew of 20 U.S. nationals re-took control later in the day. 

Ken Quinn, the ship's second mate, told CNN the pirates are holding the ship's captain in a lifeboat nearby. He says the crew released a pirate in their custody, in a bid to free their captain, but that this did not work. He says negotiations are still underway.  

Pentagon officials say the U.S. Navy destroyer Bainbridge is headed to the area.

U.S. Secretary of State Hillary Clinton said the United States is deeply concerned about the hijacking and is following it very closely. She said the world must come together to end what she called "the scourge of piracy."

The U.S. company Maersk Line which owns and operates the ship is a subsidiary of Denmark's A.P. Moller-Maersk.

The ship was the sixth vessel seized in the region within a week but it was the first American-registered vessel to be hijacked by the pirates operating off the coast of East Africa.
The ship was carrying emergency food aid to Mombasa, Kenya. A spokesman for the U.N. food agency, Nairobi-based Peter Smerdon, said the cargo includes 990 tons of vegetable oil and more than 4,000 metric tons of corn-soya blend.  

The United States and other nations deployed warships near Somalia late last year in an effort to stop pirates from seizing ships, but pirates appear to be venturing further out to sea to avoid the naval patrols.

Somali pirates have seized more than 50 ships over the past 18 months, sometimes receiving multi-million dollar payments for their release.

The pirates, who operate from bases on Somalia's east coast, are currently holding more than a dozen ships and their crews.

Some information for this report was provided by AFP, AP and Reuters.