Flotsam adds to suspicion sunk ship may have been North Korean

A life jacket and a sweet bag retrieved from the ocean has added to evidence a trawler sunk by the Japanese coast guard may have been a North Korean spy ship.

The vessel foundered off southwestern Japan after a six-hour pursuit that ended with an exchange of machine-gun fire between its crew and Japanese patrol boats.

Fifteen crew members were seen swimming in rough seas after the vessel sunk.

Japanese coast guard continued their search for the missing men, though none are believed to have survived.

The trawler had Chinese markings, and media reports some Japanese officials initially believed it might belong to Chinese smugglers.

But Zhang Qiyue, a spokeswoman for China's Foreign Ministry, was quoted by official media as saying that the boat was not Chinese.

Mr Qiyue says Beijing is "concerned" about Japan's use of military force in waters near China and would ask Tokyo for more information about the incident, the state Xinhua News Agency said.

Japanese officials have said they could raise the bullet-ridden hull of the fishing boat from the ocean floor about 100 meters underwater, and inspect it. They haven't said, however, whether they are planning such an operation.