Four people have been killed in an accident at a theme park on Australia's east coast, officials said.

Two men and two women died while on the Thunder River Rapids ride at Dreamworld, a popular attraction on Queensland's Gold Coast.

Dreamworld spokeswoman Miche Paterson said the park had been closed following the accident.

Queensland state police spokesman Kieran Self said they did not yet have any detailed information about the accident.

Aerial footage of the park showed paramedics at the rapids ride, which whisks riders in circular rafts along a fast-moving, man-made river.

The Queensland Ambulance Service said paramedics were on the scene.

The park said in a statement: "Dreamworld is working as quickly as possible to establish the facts around the incident and is working closely with emergency authorities and police to do this."

Queensland police said they were called to the scene following reports that several people had been injured by a conveyor belt.

"This is a very sad day for our city," Gold Coast Mayor Tom Tate said: "Our thoughts are with the families of those affected - and the emergency staff in attendance."