Japan to investigate China warships near Okinawa

TOKYO (Reuters) - Japan said on Tuesday it would investigate the sighting of several Chinese submarines and warships last week in the high seas near the southern island of Okinawa, where U.S. bases are concentrated in Japan.

Two submarines and eight vessels were spotted on Saturday about 140 km (90 miles) southwest of Okinawa, the first time Japan has confirmed the presence of Chinese submarines and such a large number of vessels in the area, defence ministry officials said.

"Such a situation has not happened before and we will investigate this, including whether (China has) any intentions against our country," Japanese Defence Minister Toshimi Kitazawa told reporters.

China did not violate any international law by navigating in that area, a defence ministry official said.

Beijing has been forging ahead with military modernisation. Japan, while deepening bilateral ties and expanding military exchanges with China, has often called for more transparency of Beijing's growing military spending and equipment.

Japan also lodged a complaint against China over a helicopter that flew too close to a Japanese destroyer on Thursday in the East China Sea, said Keiji Akahoshi, the chief of staff for the Japanese navy.

"We do not clearly understand the intention and the aim of the Chinese side. But flying in such proximity could affect the safe navigation of the vessel," Akahoshi said, adding that China told Japan it would look into the incident.

"We have analysed that the Chinese navy's equipment has become more modernised and its operations have technologically improved over the last few years," he said.

(Reporting by Yoko Kubota and Yoko Nishikawa; Editing by Jeremy Laurence)