Sailors walk past the US Navy's new guided missile destroyer DDG 1000 USS Zumwalt in Baltimore, Maryland. The Zumwalt is the lead ship of a class of next-generation multi-mission surface combatants.

The U.S. military says a Navy destroyer collided with a merchant ship off the coast of Japan and says there have been injuries.

In a brief written statement, U.S. Pacific Fleet in Hawaii said the Navy has requested assistance from the Japanese Coast Guard.

It said Friday that the USS Fitzgerald collided with a merchant ship 56 nautical miles southwest of Yokosuka, Japan. A U.S. defense official said there is flooding in three compartments of the Fitzgerald and there were injuries.

Pacific Fleet said the extent of injuries and damage to the Fitzgerald are "being determined," and the incident is under investigation.