Seven people have been killed and 21 injured after a race car ploughed into spectators at a motor event in Sri Lanka.

The crash occurred at the Fox Hill Supercross race on Sunday in Diyatalawa, an army base town.

Among the dead were four race officials as well as spectators, including an eight-year-old girl, the army said.

Few details have been released about the driver, his condition and whether he will face charges.

But authorities said a full police investigation was underway into the crash on the army-owned track. Diyatalawa, in central southern Sri Lanka is a former garrison town and the military maintains an academy there.

"This accident happened when the car jumped out of the running lane," police spokesman Nihal Talduwa said, according to BBC Sinhala.

According to witnesses, the crash happened soon after another car had overturned on the track.

Officials tried to slow cars down around the scene by waving yellow lights, but as the cars sped past, one red car veered off course and crashed into spectators on the side of the unguarded track.

On social media, Sri Lankans have criticised the lack of safety barriers on some stretches of the track

Footage widely shared on social media showed the aftermath of the tragedy - screams in the crowd and people rushing to the scene.

Five people were killed at the scene while two later died in hospital. Others remain in a critical condition, officials said.

On social media, Sri Lankans have questioned why there weren't greater protections, criticising the lack of safety barriers on some stretches of the track.

The event run by the Sri Lankan Automobile Sports Association has operated since 1993, but this was the first race in five years due to pandemic restrictions and issues resulting from the country's economic crisis.

Prior to the state time, organisers had opened up the event to spectators free of charge and claimed that about 100,000 people were present. (BBC)

PHOTO:A general view of the accident spot at Fox Hill motor cross racing circuit in Diyatalawa on April 21, 2024, after a car crashed into the crowd. (Getty Images)