Four people have died following an accident on a ride at Dreamworld – Australia’s largest theme park.

Police and park officials confirmed that two men and two women were killed on the Thunder River Rapids ride at 2pm local time (GMT 4am), when reports indicate a malfunction of the conveyor belt system caused a raft to be flipped.

During the incident, two of the people were thrown from the ride and the other two were reportedly trapped in the conveyor belt which takes riders back to the station. Water in the station area was drained by emergency services trying to rescue the people trapped by the conveyor belt. Six people were on the ride when it flipped on the conveyor belt.

Dreamworld is working closely with police and emergency services to establish the facts around the incident,” said Dreamworld chief executive Craig Davidson. “We a shocked and saddened by this and our hearts go out to the families involved and their loved ones.”

“Police are currently investigating an incident that occurred this afternoon at a theme park on the Gold Coast,” said a statement from Queensland Police.

“Police were called to the site at Coomera around 2.20pm (GMT 4:20am) following reports that a number of people had been injured by a conveyor belt.

“Four adults have been confirmed as being deceased.

“Police and other emergency services remain on the scene and no further information can be released at this stage.”

The family friendly attraction, which first opened in December 1988, includes a float down a river filled with artificial rapids. It is currently Australia's only river rapids ride and can reach speeds of up to 45kmph (28mph).

A man nearly drowned on a ride with a similar conveyor belt system at the park in April this year when the belt slipped, throwing him from the ride and trapping him.

The park will remain closed until further notice. Ardent Leisure, the park’s operator has said that Dreamworld's focus and priority is with the families of those involved and that it would be providing an update to the public “as soon as information becomes available.”