The Maritime Self-Defense Force destroyer Kurama collided with a South Korean cargo vessel in the Kammon Strait in Fukuoka Prefecture at around 8 p.m. Tuesday, causing a fire on the warship, the Defense Ministry said.
Three crew members of the 5,200-ton Kurama sustained minor burns and light injuries, while no one on the freighter was hurt, the ministry said.
No details about the fire were immediately available, but footage on NHK TV showed flames rising from the bow, which appeared to have suffered significant damage.
According to the ministry, the Kurama's bow houses a paint storage locker.
Defense Minister Toshimi Kitazawa told a hastily arranged news conference that the Kurama crew was scrambling to contain the fire.
The incident is "extremely regrettable," Kitazawa said.
He said in its current condition, the Kurama wasn't able to move on its own.
According to early reports, the commercial vessel is a South Korean container ship.
The news of the collision prompted Prime Minister Yukio Hatoyama to issue an instruction to the ministry to launch a quick and thorough investigation.
Hatoyama also ordered the ministry to make sure the fire was quickly contained before it could spread to other parts of the warship, according to one of his aides.
Maritime experts said the Kammon Strait is one of Japan's narrowest and toughest sealanes to pass through.
The Kurama was returning to its home port of Sasebo, Nagasaki Prefecture, after serving as the flagship in a fleet review Sunday.
