Thirty-five people have been killed and another 43 injured after a motorist deliberately drove his car into people exercising at a sports centre in the Chinese city of Zhuhai, police said.
A 62-year-old man, identified only by his family name of Fan, was detained at the centre late on Monday.
He was discovered in the car with a knife and wounds to his neck that were thought to be self-inflicted, according to a police statement.
Fan was reported to be unconscious and receiving medical care.
A motive has not been confirmed but police said a preliminary investigation found he was unhappy with the split of financial assets in his divorce.
Officers said a “number of” pedestrians were knocked down in the incident which took place on the eve of of an annual People’s Liberation Army exhibition in the southern Chinese city.
China’s president Xi Jinping has called for “all-out efforts” to treat those injured in the disaster, the country’s state media has said.
Mr Xi also said the perpetrator should be punished in “accordance with the law”.
Meanwhile, one of the four hospitals that took in casualties said it had more than 20 injured, state media reported.
Video shared on social media showed emergency services performing CPR on people at the scene, as others were told to leave the area.
Some were shared by news blogger and dissident Li Ying, who is better known on X as Teacher Li. His account posts daily news based on user submissions.
The clips showed dozens of people lying on the sports centre’s running track, with a woman in one saying: “My foot is broken.”
By Tuesday morning, searches for the incident were heavily censored on Chinese social media platforms.
A search on Weibo for the sports centre only turned up a few posts, with only a couple referring to the fact that something had happened, without pictures or details.
Articles by Chinese media about the incident from Monday night were taken down.
Chinese internet censors take extra care to check social media ahead of and during major events, such as the meeting of the National People’s Congress, where the government announces its major policy initiatives for the coming year.
The sports centre for the city district of Xiangzhou regularly attracts hundreds of residents, where they can run on the track field, play soccer and take part in social dances. Following the incident, the centre announced that it would be closed until further notice.
China has seen a number of attacks in which suspects appear to target random people such as schoolchildren.
In October, a 50-year-old man was detained after he allegedly used a knife to attack children at a school in Beijing. Five people were injured.
In September, three people were killed in a knife attack in a Shanghai supermarket.