Three U.S. Navy amphibious ships and two minesweepers left Sasebo port in Nagasaki Prefecture on Tuesday, heading for an undisclosed destination.
The ships are the 40,532-ton amphibious assault ship USS Essex, the 15,726-ton dock landing ships USS Germantown and USS Fort McHenry, and the 1,312-ton minesweepers USS Guardian and USS Patriot.
U.S. military authorities declined to provide any details concerning the deployment or final destination of the ships, but the movements are believed to be connected to a possible attack on Afghanistan by U.S.-led multinational forces in response to the Sept. 11 terrorist attacks in New York and Washington.
According to Sasebo base sources, the ships will pick up marines at White Beach in Katsuren, Okinawa Prefecture, before heading to their destination.
The Essex left Sasebo briefly on Sept. 12 and 22 following the terror attacks.
The Maritime Self-Defense Force kept close watch of the sea around Sasebo and put a destroyer and two patrol helicopters on standby.