A containership and a US Navy destroyer collided off Japan yesterday, with seven of the warship's sailors still missing.

The USS Fitzgerald collided with the 2,858-teu ACX Crystal (built 2008) at about 2.30am local time, 56 nautical miles southwest of Yokosuka, Reuters reported.

Three crew onboard the US ship were evacuated, including the commanding officer.

Although the circumstances of the collision are still unclear, Japan's public TV showed aerial footage of the Fitzgerald with a large dent on its right.