Hijackers seized a German-owned ship in the pirate-infested waters between Somalia and Yemen on Saturday, a U.S. Navy spokesman said.

Pirates captured the Maltese-flagged MV Patriot in the Gulf of Aden about 150 nautical miles southeast of the Yemeni coastal city of Muqalla, said U.S. Navy 5th Fleet spokesman Lt. Nathan Christensen.

An official from the German Foreign Ministry could not immediately confirm the ship's capture.

Andrew Mwangura of the Mombasa, Kenya-based East African Seafarers' Assistance Program, a group that monitors pirate activity off the African coast, said the ship has 17 crew members but could not give their nationalities.

He said the large cargo vessel is designed to carry grain, but said he did not know what cargo it contained when it was captured. A Web site citing the ship's specifications also noted that the single-decker carrier ship is designed to carry grain and bales.

Many of the ships crossing the Gulf of Aden, one of the world's busiest shipping lanes, are carrying food to eastern African nations. One of those was the MV Maersk Alabama, a U.S.-flagged vessel hijacked this month, which led to a five-day standoff with the U.S. Navy.

Also in the Gulf of Aden on Saturday, naval vessels from the U.S., Germany and China went to the aid of a Philippine chemical tanker stranded without fuel in waters near Somalia days after pirates freed it.

Maria Elena Bautista, administrator of the Maritime Industry Authority, said a U.S. Navy ship provided five days worth of diesel fuel for the MT Stolt Strength, which was drifting about 60 miles east of the Somali coast. The pirates seized the ship in November as it sailed through the Gulf of Aden with a cargo of phosphoric acid.

Pirates have attacked more than 100 ships off the Somali coast over the last year, reaping an estimated $1 million in ransom for each successful hijacking, according to analysts and country experts.

Somalia, which was plunged into anarchy in 1991 after its dictator was overthrown. The war-wracked country has become the pirates' de facto base, and they are often viewed as heroes, using ransom money to build lavish villas for their families.