A U.S. Navy ship capable of identifying metal on the ocean floor has joined the search for an Indonesian passenger plane that vanished from radar screens last week with more than 100 people on board.

Indonesian officials say the vessel Mary Sears reached a site Tuesday where ships spotted metal during their search for the missing Adam Air jet on Monday.

Indonesia has been unable to identify the metal objects, which were found in three spots off the coast of West Sulawesi province. The objects are about 1,000 meters below the surface.

The Adam Air Boeing 737 disappeared from radar screens January first during a flight from Surabaya - on Java - to Manado - on Sulawesi.

A separate team of U.S. experts is also helping with the search for the aircraft. Indonesian rescuers are also scouring the jungle on Sulawesi for any signs of the plane.

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