Two children dead in dam car crash in Queensland

Two children, aged 5 and 13, have been killed in a serious car crash in Queensland's southeast in Australia when the vehicle plunged into a dam.

A 6-month-old baby and a 1-year-old toddler are in Queensland Children's Hospital.

The toddler is in a critical condition.

Two adults, a woman in her 30s and a man in his 20s who has leg injuries, have both been transported to Princess Alexandra Hospital by road.

Two adults and four children were in the Land Rover Discovery when the vehicle crossed onto the wrong side of the road and broke through a road barrier.

The vehicle then rolled down an embankment before flipping and ending up on its roof in the dam.

Police and emergency services have been at the scene of the serious single-vehicle crash where the car plummeted into Wyaralong Dam around 2pm on Sunday.

Passers-by helped pull people out of the submerged car, including two off-duty doctors and a paramedic on a day off.

Three rescue helicopters and more than a dozen emergency vehicles attended the incident. Photo / ABC

"It's a tragic and confronting scene," Queensland Police Inspector Douglas McDonald said.

"It's absolutely tragic for the family.

"It was fantastic work to help rescue.

"Their actions were pivotal in making sure this wasn't worse."

Police are still investigating into the circumstances which led to the crash.

The vehicle is still submerged and police divers are attending to the scene.

"It's relatively shallow. The vehicle is on its roof. The wheels can be seen above water," he said.

Three rescue helicopters and more than a dozen emergency vehicles attended the incident.

The accident happened at a location off Beaudesert Boonah Road near the Overflow Estate Winery around 2pm on Sunday.

Queensland Police have closed the road in both directions and are advising motorists to avoid the area.

One police vehicle flipped as it rushed to the scene, but no officers were hurt.

The accident happened at a location off Beaudesert Boonah Rd. Photo / ABC