Japan’s Defense Ministry has lodged a formal protest with China following two incidents this week in which Chinese JH-7 fighter-bombers made what the ministry called “unusual approaches” to Japan Air Self-Defense Force (ASDF) surveillance aircraft over international waters in the East China Sea.

According to Japan’s Defense Ministry, Chinese Xian JH-7 fighter-bombers made two unusually close approaches to ASDF YS-11EB electronic intelligence aircraft over international waters on Wednesday and Thursday. In the first incident, a JH-7 flew within 70 meters of the Japanese aircraft and maintained that distance for about 15 minutes. 

The following day, another JH-7 closed to within 30 meters vertically and stayed in proximity for roughly 10 minutes. Both encounters occurred in international airspace above the East China Sea and caused no damage or injuries, but the ministry described the distances as “short enough to potentially cause a collision.”

“Such unusual approaches by Chinese military aircraft pose a potential risk of accidental collision and have raised serious concerns,” Japan’s Defense Ministry said in its official statement cited by Japan Times. “We have strongly urged the prevention of such incidents from recurring.”

The ministry said the YS-11EB aircraft were operating outside Japanese territorial airspace and did not interfere with any Chinese military activity. Japan’s Foreign Ministry reported that Vice Foreign Minister Takehiro Funakoshi summoned Chinese Ambassador Wu Jianghao on Thursday to protest the incidents. 

The flights took place near the disputed Senkaku Islands, which are administered by Japan but claimed by China, where they are known as the Diaoyu Islands. The area has been a frequent site of military and coast guard activity by both countries.

There was no immediate response from Beijing. In past incidents, Chinese authorities have accused Japan of conducting close surveillance and “dangerous actions” near Chinese military operations. Japan has denied these claims and maintains that its aircraft operate strictly in accordance with international law.

The aircraft involved included the JH-7, a twin-seat, twin-engine Chinese fighter-bomber developed by the Xi’an Aircraft Industrial Corporation, and the YS-11EB, a Japanese-made electronic intelligence variant of the NAMC YS-11 turboprop airliner. The YS-11EB is used by the ASDF’s Electronic Intelligence Unit for monitoring military signals and movements.

Similar aerial encounters occurred last month. On June 7 and 8, Chinese J-15 fighters launched from the aircraft carrier Shandong approached a Maritime Self-Defense Force P-3C maritime patrol aircraft over the Pacific Ocean. On June 7, the Chinese aircraft came within 45 meters; the next day, a J-15 crossed just 900 meters in front of the Japanese aircraft’s flight path.

Japan’s Defense Ministry said those actions, along with this week’s maneuvers, are part of a pattern of increased Chinese military activity in airspace surrounding Japan, particularly along the First Island Chain.