Japan said J-15 warplanes operating from two Chinese aircraft carriers in the Pacific carried out risky manouvres around patrol planes.

Japan has protested to Beijing over what was described as Chinese fighter jets’ “near-miss” manoeuvres near Japanese maritime patrol planes over the Pacific where China’s two operational aircraft carriers were spotted deployed simultaneously for the first time last weekend.

Japan’s Kyodo news agency reported on Thursday that a Chinese J-15 warplane from the Shandong aircraft carrier flew within 45 metres (147 feet) of a Japanese P-3C maritime surveillance plane and made other “dangerous manoeuvres” during incidents on Saturday and Sunday.

“We have expressed serious concern to the Chinese side and solemnly requested prevention of recurrence,” Japan’s Chief Cabinet Secretary Yoshimasa Hayashi said.

According to Japan’s defence ministry, P-3C aircraft, belonging to Japan’s Maritime Self-Defense Force based on the island of Okinawa, were conducting surveillance over international waters in the Pacific when they encountered Chinese warplanes.

On Saturday, a J-15 from the Shandong chased a Japanese P-3C patrol aircraft for about 40 minutes. Then, on Sunday, a J-15 fighter chased a P-3C for 80 minutes, crossing in front of the Japanese aircraft at a distance of only 900 metres (2,952 feet), the ministry said.

“Such abnormal approaches by Chinese military aircraft could potentially cause accidental collisions,” the defence ministry said in a statement on Wednesday, attaching close-up images of the J-15 jet it took on Sunday. There was no damage to the Japanese planes or harm caused to the aircraft crew, the ministry added.

Hayashi, the top Japanese government spokesperson, said Tokyo will maintain communications with Beijing at various levels and will also ensure the monitoring of airspace around Japan’s territories continues.

The last time a similar incident was reported was more than a decade ago in May and June 2014, when Chinese Su-27 fighter jets flew within 30 metres (98 feet) of Japan’s military planes.

The Kyodo news agency also reported that the Shandong aircraft carrier conducted takeoff and landing drills on Monday to the north of Japan’s southernmost Okinotori Island, inside the country’s exclusive economic zone (EEZ). The Liaoning carrier was also spotted inside the EEZ on Saturday before moving outside the zone where it also conducted takeoffs and landings on Sunday.