Thirty-five people have died and 43 have been injured after a car was driven into people exercising at a sports centre in the southern Chinese city of Zhuhai, state television CCTV reported on Tuesday.

A 62-year-old man was detained after the incident on Monday night, on the eve of the country’s premier aviation exhibition by the People’s Liberation Army, hosted annually in the city.

It was not immediately clear whether it was an attack or an accident. No motive was mentioned, and police said investigations were continuing.

Police identified the man only by his family name of Fan, consistent with the usual practice by Chinese authorities.

By Tuesday morning, searches for the incident were heavily censored on Chinese social media platforms. A search on Weibo for the sports centre turned up 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.

Chinese internet censors take extra care to scrub social media before 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, where residents can run on the track, play football and dance, regularly attracts hundreds of visitors. After the incident, the centre announced it would be closed until further notice.

China has recently 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.