EMERGENCY crews have been called to Dreamworld after reports four visitors were critically injured in an accident on a ride at the theme park.
Paramedics and fire crews were on scene at Dreamworld at Coomera after they received emergency calls just after 2pm.
Nine News have reported four people have died, however emergency services were yet to confirm any deaths.
Queensland Police said it appeared one person had become caught in a conveyor belt.
It was understood one of the patients was unconscious and CPR was being performed.
Nine News reported the accident happened on the Thunder River Rapids ride.
Gold Coast mayor Tom Tate said it is a "very sad day for our city".
"Our thoughts are with the families of those affected – and the emergency staff in attendance," he said.
"I urge everyone to show the respect needed as the relevant authorities undertake investigations in to what has occurred.
"A truly sad day for all."
A concerned mother whose daughter was at Dreamworld at the time of the incident voiced relief to Facebook after she was told those involved were not children.
"Ok I'm here at park and have been informed the ppl (sic) in the accident are over 30 now to find my girl they are evacuating park now thanks all," she wrote.
The story, Dreamworld accident: Reports of deaths after conveyor belt accident, first appeared on the Sydney Morning Herald.