Tokyo [Japan], December 7 (ANI): Chinese fighter aircraft locked fire-control radar on Japanese military jets over international waters on Saturday, according to Japan's Defence Ministry, Japanese state media reported on Sunday.

The incident comes amidst simmering tensions between Tokyo and Beijing.

At a press briefing in the early hours of Sunday in Tokyo, Japanese Defence Minister Shinjiro Koizumi gave details of two episodes of a Chinese J-15 launched from a Chinese Liaoning aircraft carrier intermittently locking its radar on Japanese F-15 fighter planes over international waters southeast of Japan's Okinawa Prefecture, Kyodo reported.

Koizumi called the incidents 'dangerous and extremely regrettable' and said Japan has lodged a strong protest and told China to ensure there is no repeat.

'China's intentions are unclear, but if it is to locate (aircraft), there is no need to do that intermittently,' said an official of Japan's Defence Ministry, who held a press briefing after Koizumi spoke.

On December 6, China's navy conducted training flights in the Pacific Ocean from the Liaoning after the ship passed through waters off Okinawa Prefecture, prompting the Japanese SDF to scramble aircraft, Kyodo reported.

China commissioned its third aircraft carrier, the Fujian, last month.

The Japanese Defence Ministry spotted the Liaoning sailing in the East China Sea on Friday, around 420 kilometers north of Kuba Island, an islet controlled by Japan but claimed by China.

Joined by three Chinese destroyers, the aircraft carrier then headed toward the Pacific Ocean and conducted the training flights in waters some 270 km west of Okidaito Island, the ministry said.

China on Sunday sharply rebutted Japanese protest over what it called a 'regular carrier-based fighter jet flight training' in the east of Miyako Strait and alleged Japanese Self-Defence Force aircraft had 'seriously interfered' with Beijing's 'normal training activities' and 'posed a severe threat to flight safety.

Chinese state media Global Times cited a statement by PLA Navy spokesperson, Senior Captain Wang Xuemeng, that the jet flight training was publicly announced in advance and accused the Japanese Self-Defence Force aircraft of 'interfering' with Chinese activities.'Japan's relevant hype is completely inconsistent with the facts, the People's Liberation Army (PLA) Navy spokesperson said in a statement as quoted by the Global Times.

'We firmly demand that Japan immediately cease its slander and smearing, and strictly restrain its frontline operations. The PLA Navy will take necessary measures in accordance with the law to resolutely safeguard its own security and legitimate rights and interests,' he said.

In June this year too, Chinese jets reportedly flew dangerously close to a Japanese patrol aircraft near Okinawa.

Okinawa is close to Taiwan, which Beijing regards as a renegade province to be reunified with the mainland, by force if necessary.

Meanwhile, Taiwan's government described that build-up as posing a threat to the Indo-Pacific region. Japan said it was monitoring Chinese activity closely.

Tensions between Tokyo and Beijing have escalated following Japanese Prime Minister Sanae Takaichi's remarks that a military attack on Taiwan could present a 'survival-threatening situation' for Japan, indicating the Japanese SDF's potential involvement in response to such a scenario. (ANI)