China has lodged a strong protest and made representations with the Japanese after what it described as a "forceful break-in" at its embassy in Tokyo, the Chinese foreign ministry said on Tuesday.
An individual who claimed to be an active-duty officer of the Japan Self-Defense Forces scaled the wall and forcibly entered the Chinese Embassy on Tuesday morning, ministry spokesperson Lin Jian told a regular press conference.
"The individual admitted that his actions were illegal and threatened to kill Chinese diplomatic personnel in the so-called name of God," Lin said.
China is "deeply shocked" by the incident, Lin said, urging Tokyo to conduct a thorough investigation, punish those responsible and provide an explanation.
"The Japanese side must effectively guarantee the safety of the premises and personnel of Chinese embassies and consulates in Japan, reflect on and correct its policies towards China, and fundamentally prevent such incidents from occurring again," he said.
The Japanese defence ministry did not immediately respond to a request for comment.
Ties between the two Asian neighbours have deteriorated after Japanese Prime Minister Sanae Takaichi suggested last November a hypothetical Chinese attack on Taiwan, the democratically-governed island China claims its own, could trigger a military response from Tokyo.
Japan will also downgrade its description of ties with China from "one of its most important" in an annual diplomatic report, according to a draft reviewed by Reuters, as relations with Beijing worsen.
The 2026 Diplomatic Bluebook, which Prime Minister Sanae Takaichi's government is expected to approve next month, will instead describe China as an important neighbour and the relationship as "strategic" and "mutually beneficial."
The draft cites a series of confrontations with Beijing over the past year, including export controls on rare earths, radar lock-ons targeting Japanese military aircraft and increased pressure around Taiwan.