The U.S. Navy says the 20 crew members held captive by Somali pirates aboard an arms-laden Ukrainian ship appear to be healthy.

The Navy’s Lt. Nathan Christensen says the pirates who seized the ship three weeks ago allowed the mostly Russian crew to line up on the deck Sunday so U.S. sailors on nearby vessels could see them.

Navy spokesman Christensen said Monday that the crew of the MV Faina looked healthy. He was speaking from the Middle East headquarters of the U.S. Navy’s 5th Fleet in Bahrain.

The ship was hijacked Sept. 25 off Somalia’s lawless coast. It is carrying tanks, rifles and ammunition.

U.S. warships surround the vessel, and American sailors maintain radio contact with the pirates and crew.