Police had detained a 62-year-old man at the sports centre in the southern Chinese city of Zhuhai following the ramming late on Monday, on the eve of the country's premier aviation exhibition by the People's Liberation Army that's hosted annually in the city.
Police identified the man only by his family name of Fan, consistent with the practice by Chinese authorities.
Fan was discovered in the car with a knife, with wounds to his neck thought to be self-harm injuries, according to the statement.
He is unconscious and receiving medical care.
He was dissatisfied with the split of financial assets in his divorce, according to a preliminary investigation, police said.
For almost 24 hours after the crime took place, it was unclear what the death or injury toll was.
Police arrested a 62-year-old man following the ramming at a sports centre in Zhuhai. (AP PHOTO)
One of the four hospitals that took in people for treatment said it had more than 20 injured, state media reported on Monday.
AP reporters call to the hospitals in the city were unanswered, or directed towards other hospitals.
On Tuesday morning, searches for the incident on Chinese social media 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 something had happened, without pictures or details.
Articles by Chinese media about the incident from Monday night were taken down.
Outside of China's Great Firewall, on X, however, videos were able to circulate.
They 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.
Dozens of people were lying prone on the running track in the sports centre in the videos. In one, a woman says, "My foot is broken."
That same video showed a firefighter performing CPR on a person, as people were told to leave the scene.
Chinese internet censors take extra care to scrub 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 social dance.
Following the incident, the centre announced 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.
