A Chinese man attacked Ambassador Uichiro Niwa’s car in another symbolic blow to tensed relations between the two countries over territorial disputes.

Japan’s ambassador to China was traveling with his wife and two staff when two cars blocked the road. An official at the Japanese embassy stated: “A man jumped out of one of the two vehicles, ran over to the ambassador’s car and ripped the Japanese flag off it”.

According to Financial Times, the Japanese embassy has lodged a protest and requested a criminal investigation on the incident. Officials from the Chinese foreign ministry expressed their regret over the incident and said it would ensure the safety of Japanese nationals and companies in China.

China-Japan relations took a turn for the worse when several Hong Kong activists landed on the disputed islands off the East China Sea to defend Chinese claims. The activists were arrested by the Japanese Coast Guard which sparked anti-Japan sentiment in Beijing.

Japan is set to place new ambassadors in its diplomatic front, including Ambassador Uichiro Niwa following his critical remarks on Tokyo Governor Shintaro Ishihara’s plan to buy the Senkaku islands.