China expresses grave concern over recurring malicious incidents that threaten the security of Chinese embassy and consulates in Japan, Chinese Foreign Ministry spokesperson Lin Jian said on Wednesday at a regular press briefing.

Lin pointed out that Kodai Murata, a second lieutenant of Japan's Ground Self-Defense Force, illegally broke into the Chinese Embassy in Japan armed with a knife. Nearly three months have passed, yet Japan's investigation and handling of the case are still proceeding slowly, he added.

"The incident once again exposes deep-seated issues in Japan," Lin said, urging the Japanese side to reflect on and correct its policies and conduct, carry out a thorough probe and provide a responsible explanation to China.