Canberra, Oct 25 (IANS): At least four people were killed on Tuesday in an accident at a theme park in Australia's Gold Coast city, police said.

The incident occurred on the Thunder River Rapids ride at the Dreamworld theme park, the ABC reported.

Dreamworld said they were working "quickly to establish the facts around the incident and is working closely with emergency authorities and police to do this".

The Thunder River Rapids ride is described on Dreamworld's website as a "moderate thrill".

"Travel down a foamy water track past the Gold Rush country, speeding up to 45 km/h through the turbulent rapids," the website reads.

It said up to six people could be seated per ride and riders must be 120 cm tall.

It is unclear exactly how the accident occurred, but there are reports the craft flipped and trapped the passengers, the police added.

In April, emergency services said a man nearly drowned after he was thrown from the log ride at Dreamworld.

In September, several people had to be evacuated from a rollercoaster at nearby Seaworld during the school holiday season. But no one was injured.