In this photo released by Japan's 5th Regional Coast Guard, clouds of black smoke billow from Shoko Maru, a 998-ton Japanese oil tanker, after it exploded off the southwest coast near Himeji port, western Japan, Thursday, May 29, 2014.
Divers on Friday were searching for the captain of an oil tanker that exploded and sank off the Japanese coast.
The coastguard deployed six patrol ships, as well as several airplanes, to the area where the nearly 1,000-tonne tanker, Shoko-maru, went down around 10 hours after it erupted in a fireball on Thursday.
Seven of the eight Japanese crew were rescued, including one who remained unconscious with severe burns covering his entire body, but the vessel's 64-year-old captain was still missing
After the accident, the transport ministry urged tanker operators nationwide to step up safety measure, a spokesman said.
The fire was likely sparked as a crew member used a grinder to remove rust on the ship, Transport Minister Akihiro Ota told a press conference.