Two Japanese men and a Chinese woman were injured in a knife attack at a restaurant in Shanghai on Tuesday, authorities said.

A 59-year-old man armed with a fruit knife entered the restaurant at the Shanghai World Financial Centre in Pudong at around noon and attacked the victims before being detained, police said.

The victims were taken to a local hospital for treatment.

One of them was a senior executive at a Japanese company housed in the commercial complex where the attack took place.

Police said the suspect had a history of mental illness and that an investigation into the motive for the attack was ongoing.

Several Japanese firms operate offices in and around the Shanghai World Financial Centre.

A Japanese employee working in the financial district said that several police officers arrived at the restaurant shortly after the attack. “I was shocked because I used to go to that restaurant often,” he said.

The attack comes against the backdrop of strained relations. Ties between China and Japan have worsened since prime minister Sanae Takaichi last year spoke about the possibility of her country deploying its military in the event of a Chinese attack on Taiwan.

China argues that Taiwan, a self-governed island, is a breakaway province and seeks to reunify it with the mainland.

In the aftermath of the attack, Japan’s embassy issued an advisory urging its citizens in the country to remain vigilant and take precautions, The Japan Times reported.

Chief cabinet secretary Minoru Kihara told a press conference in Tokyo that the Japanese foreign ministry and its diplomatic mission had asked China to “clarify the facts of the case and give a clear explanation” and “severely punish the suspect”, Mainichi reported.

The attack has revived concerns within the Japanese expatriate community in China.

In September 2024, a 10-year-old Japanese boy was fatally stabbed in Shenzhen. In June 2024, a Japanese mother and her child were injured in a knife attack while waiting at a school bus stop in Suzhou. A Chinese woman who tried to protect them later succumbed to her injuries. The assailant was sentenced to death and executed in April last year.