The Ministry of National Defense on Thursday criticized Japan for interfering in a Chinese military drill on the open sea, calling the move "an extremely dangerous provocation".

A Japan Maritime Self-Defense Force warship intruded into a sea area in the West Pacific where the Chinese navy was holding an exercise on Oct 25, Yang Yujun, spokesman for the ministry, said a news briefing.

China had publicized the exercise areas in advance via international maritime organizations in accordance with international practice, alerting foreign vessels and planes to take precautions.

But the Japanese warship entered the area and stayed there for three days before leaving on Oct 28, Yang said.

Japan also sent reconnaissance aircraft and ships to closely monitor the Chinese navy ships during the drill.

"The actions of the Japanese ships and planes not only interfered with our normal exercises but also endangered the safe navigation of Chinese ships and planes, and might lead to misjudgment and accidental injuries".

The Ministry of National Defense has protested to Japan over the issue, Yang said.

He called on Japan not to disturb China's legitimate military drills and make sure no such incidents recur.

"Otherwise, all consequences that arise will be borne by the Japanese side," Yang said, adding that China reserves the right to take further actions.

Ding Hao, a senior researcher at the Academy of Military Sciences, said Japan's action shows their strong objection to the PLA's activities in the area.

"Japan also wants to take the opportunity to collect military information on China, which can be regarded as a strong provocative action because military drills are highly confidential."

The eight-day drill, which began on Oct 24, is the first open-sea exercise in which maritime and air forces from all three of China's fleets took part.

It is expected to improve high sea combat abilities and hone strategies for using information technologies.

Yang urged Japan to accept and get accustomed to "reasonable and legitimate military activities of other countries."

Commenting on Japan's 2014 defense budget report, which increasingly targeted China, Yang said Japan has kept playing up "military threats" from China to serve its own military expansion.

Ding said Japan wants to hold China responsible for disputes between the two countries, despite the fact that it is Japan that has kept creating tensions in the region, with issues from the Diaoyu Islands to the Yasukuni war shrine.

"Japan's moves aim to support its domestic military policy, at the cost of bringing huge harm to mutual trust with China. The problem can only be intensified if Japanese leaders continue their confrontational policies," Ding said.

Regarding Japanese Prime Minister Shinzo Abe's recent remarks that Japan should take a stronger leading role in Asia and confront China, Yang questioned whether a country that is reluctant to make a profound reflection on its history and is seeking to challenge the post-war order can take a leading role in Asia.

In an interview with the Wall Street Journal on Oct 26, Abe said one way that Japan could "contribute" to the region would be countering China.

Contact the writers at lixiaokun@chinadaily.com.cn and zhangfan@chinadaily.com.cn