The U.S. Navy's USS Fitzgerald has collided with a Japanese vessel, CBS News national security correspondent David Martin reports.

The collision occurred at 2:30 a.m. local time on June 17, about 56 nautical miles off of Yokosuka, Japan. The collision was serious, although further details are still emerging. A Department of Defense official says the Fitzgerald is not under her own power, and the Japanese are sending out tugs. The extent of the damage and personnel injuries is being determined, and the incident will be investigated. As of 6:10 p.m. EST, the 7th Fleet said there were no reports of casualties.

Live footage shot from a helicopter Saturday morning by Japanese broadcaster NHK showed heavy damage to the mid-right side of the Navy ship, which appeared to be stationary in the water. People were standing on various parts of the deck.

The USS Fitzgerald, an Arleigh Burke-class guided missile destroyer commissioned in 1995, is based in Yokosuka, according to the Navy. Its crew includes roughly 23 officers, 24 chief petty officers and 291 enlisted members of the Navy.

Japan and U.S. relations strengthened in 2015 through the release of revised guidelines, which provide new and expanded forms of security-related cooperation, according to the State Department. Japan provides bases as well as financial and material support to U.S. forces to maintain stability in the region.