On Saturday, a Chinese J-15 jet from the aircraft carrier Shandong chased a Japanese P-3C patrol aircraft for about 40 minutes, the ministry said.

On Sunday, a J-15 chased a P-3C for 80 minutes, crossing in front of the Japanese aircraft at a distance of only 900m, it said.

At one point on both days, a Chinese J-15 flew as close as 45m to a Japanese aircraft, the ministry said.

The P-3C aircraft, belonging to Japan’s Maritime Self-Defense Force based in the island of Okinawa, were conducting surveillance over international waters in the Pacific, the ministry said.

“Such abnormal approaches by Chinese military aircraft could potentially cause accidental collisions, and we have expressed serious concern and strongly requested prevention of recurrence,” the ministry said, attaching close-up images of the J-15 jet it took on Sunday.

Earlier this week, Tokyo said the Shandong and another Chinese carrier the Liaoning were conducting simultaneous operations in the Pacific for the first time, describing it as a move signifying Beijing’s intention to further widen its capabilities beyond its borders.

Beijing on Tuesday said the operations were a “routine training” exercise that did not target specific countries.

In 2014, Tokyo said it spotted Chinese military aircraft flying as close as 30 metres to its military aircraft over the East China Sea and protested to Beijing.