TOKYO (AP) — Black smoke was billowing Tuesday from a cruise ship docked at a port near Tokyo as crewmembers and dozens of firefighters and coast guard personnel battled to control it.

The cause of the smoke was not immediately known, and the coast guard reported no injuries.

The local coast guard branch said the smoke was coming from the top deck of the Asuka II, one of Japan's largest cruise ships.

No passengers were on the ship, its operator NYK Line said. The company said 153 crew members were on board for essential duty and were fighting the fire.

The cruise ship has been docked in Yokohama Port, west of Tokyo, since early April after returning from Singapore where it had undergone maintenance.

Yokohama Port is where the Diamond Princess cruise ship earlier this year had a coronavirus outbreak that infected more than 700 people. The ship has since left.