BEIJING, June 12 -- China on Thursday blamed Japan for a close encounter between Chinese and Japanese military planes, saying it was Japan's long-term close surveillance and scouting of China's aircraft that led to tensions over the East China Sea.

Foreign Ministry spokeswoman Hua Chunying said at a daily press briefing, "The tension was completely triggered by dangerous acts of Japanese warplanes towards a Chinese warplane, while Japan disregards the facts and makes a false countercharge, openly defames China and hypes up the so-called China threat."

She continued, "China firmly opposes this and lodges strong protest."

According to the Chinese Defense Ministry, two F-15 jet fighters tailed a Tu-154 plane of China over the East China Sea from 10:17 a.m. to 10:28 a.m. on Wednesday. They approached the Chinese airplane as close as about 30 meters, seriously threatening the safety of the Chinese plane.

Also on Wednesday morning, two Japanese surveillance planes intruded into the East China Sea Air Defense Identification Zone. Two J-11 jet fighters of the Chinese Air Force took off to identify them. They kept more than 150 meters away from the Japanese planes during the whole process.

"The performance of the Chinese pilots have been professional, standard and restrained, while the moves by the Japanese pilots were dangerous and obviously provocative," Defense Ministry spokesman Geng Yansheng said.

Hua said this is not the first time that Japan blamed its victims, adding that Japan has closely scouted and disrupted China's normal flying for a long time, which posed grave threat to Chinese warplanes' safety and caused tensions over the East China Sea.

According to a Defense Ministry statement last month, two Japanese airplanes, OP-3C and YS-11EB, intruded into the East China Sea Air Defense Identification Zone on May 24 to scout and interfere with China-Russia naval drills.

"Instead of reflecting on its own mistakes, Japan has been making remarks that totally distort facts from time to time, maliciously attacking China and intentionally deceiving the world," said Hua. "We can't help but ask what does Japan really want to do?"

She said, "Considering Japan's recent moves to amend its constitution, expand its military force, play up regional threat, produce tension and confrontation, we need to have a clear mind on and keep high alert to Japan's real intention. Japan must honestly explain its intention to the world."

She added that China reserves the right to take further measures.