Three people were killed and 15 others injured in a knife attack at a supermarket in Shanghai on Monday, the state-run Xinhua news agency reported, extending a series of stabbing incidents across China this year.
The victims were immediately rushed to hospital for treatment, according to Xinhua on Tuesday, but three died.
The assailant, a 37-year-old man surnamed Lin, was detained by the police who received a report of the incident at 9:47 p.m. local time (1447 GMT), Xinhua said.
An investigation is underway.
Public stabbing incidents have risen over the years in China, with authorities often blaming mental illness. Children at schools are a common target.
In September, a 10-year-old Japanese student was fatally stabbed by an attacker meters from his school in the southern Chinese city of Shenzhen.
That incident along with a June knife attack on two Japanese nationals in Suzhou, a major city in eastern China, has stoked security concerns among members of the Japanese community in China.
Stabbing incidents are rare in Shanghai but not unprecedented.
In 2022, a man went on a stabbing spree at a major hospital in the Chinese financial hub, injuring 15 people.
The man, whom authorities said was "resentful of society" after an investment fell through, was sentenced to death a year later.