A car ploughed into a crowd outside a stadium in the Chinese city of Zhuhai on Monday evening, injuring multiple people, police have said.
The 62-year-old male driver, surnamed Fan, has been arrested.
Local reports estimate that at least 20 people, many of whom were struck while exercising at Zhuhai Sports Centre, were injured and have been sent to hospital.
The incident took place despite heightened security in the city, which is also hosting a major civil and military airshow.
Most videos of the incident posted by eyewitnesses have since been scrubbed off Chinese social media, but some footage still circulating online show many people lying on the ground and being attended to by paramedics and bystanders.
Some of the victims appear to be unconscious.
An eyewitness, Mr Chen, told Chinese news magazine Caixin that at least six groups of people had gathered at the stadium for their regular walks when the incident happened.
The groups use a designated walking path that traces the stadium’s perimeter.
Mr Chen said his group had just completed its third lap around the stadium when a car suddenly charged towards them at a high speed, “knocking down many people”.
“It drove in a loop, and people were hurt in all areas of the running track – east, south, west, and north,” another eyewitness told Caixin.
The outlet reported that many elderly people, as well as teenagers and children, were among those injured.
It is unclear whether the incident was linked to the high-profile Zhuhai Airshow, which started on Tuesday at a venue just 40km (24 miles) away from the stadium. China is showcasing its latest warplanes and attack drones at the show, and top Russian official Sergei Shoigu is expected to attend.
Several entrances and exits to the sports centre have been closed during the airshow to facilitate “control”, the centre’s management said on Tuesday.
China has seen a spate of violent attacks on members of the public in recent months.
In September, a man went on a stabbing spree at a supermarket in Shanghai, killing three people and injuring several others.
In that same month, a 10-year-old Japanese student died a day after he was stabbed near his school in southern China.