The Japanese government has expressed its concerns to China via diplomatic channels over the seizure of a Mitsui O.S.K. Line Ltd ship by a Chinese court in connection with a case over wartime claims, Kyodo news agency reported on Monday. A Chinese maritime court in Shanghai seized the ship on Saturday, saying the company had failed to pay compensation stemming from a wartime contractual obligation. Japan’s top government spokesman said the ship seizure, apparently the first time the assets of a Japanese company have been seized in a lawsuit concerning compensation for World War Two, was “extremely regrettable”.