Nine people were injured, one critically, after a car crashed into a crowd during a demolition derby in southeastern Australia, police said.

The car had been taking part in a race in the town of Walcha on Saturday night when it drove through a fence and hit the grandstand, New South Wales police said in a statement.

The race, part of the annual Walcha Motorcycle Rally, had been a demolition derby - a type of motorsport where drivers ram their vehicles into one another.

Police said the ages of the injured bystanders ranged from 20 to 75, while the critically injured person was a 54-year-old man. An investigation is underway, they stated.

Authorities reported that the 27-year-old driver of the car had been involved in a collision on the track right before driving into the fence.

In a statement published on the Walcha Motorcycle Rally's Facebook page, the Walcha Council expressed that it was shocked and stunned at the unfortunate accident. They further stated their commitment to working with authorities to examine the circumstances leading to the incident.

Brendan Moylan, a member of parliament for Northern Tablelands, thanked emergency responders and bystanders for their swift and professional actions at the scene. My thoughts are with everyone affected, he wrote on Facebook.

Former deputy prime minister Barnaby Joyce also extended his heartfelt thoughts to those injured, calling the incident a sad end to such a great event.

The Walcha Motorcycle Rally describes itself as a grassroots event for motorcycle enthusiasts.