An individual claiming to be an active-duty officer of the Japan Self-Defense Forces scaled a wall and entered the Chinese Embassy in Tokyo earlier in the day, Chinese foreign ministry spokesperson Lin Jian said at a regular press briefing.

Lin said the individual admitted the act was illegal and threatened to kill Chinese diplomatic personnel “in the name of God,” prompting what Beijing described as shock and concern over the safety of its staff.

China called on Japan to conduct a thorough investigation, hold those responsible accountable and ensure the security of Chinese embassies and consulates.

JJapan’s defence ministry did not immediately respond to requests for comment regarding the incident or the alleged affiliation of the individual involved.

The incident comes against a backdrop of deteriorating relations between China and Japan. Tensions have risen since Japanese Prime Minister Sanae Takaichi suggested that a potential Chinese attack on Taiwan could prompt a military response from Tokyo.

Japan is also expected to downgrade its description of bilateral ties in an upcoming diplomatic report, citing a series of confrontations over the past year, while Beijing has reiterated calls for Tokyo to withdraw what it views as provocative remarks.