Three dead in horror bus, 4WD crash in Queensland

Police said a four-wheel drive pulling a caravan collided with a bus carrying 33 people in the opposite direction in a 100km/h zone.

Along with the three fatalities, a number of people were treated at the scene, with one man airlifted to a nearby hospital due to the severity of his injuries.

A man was airlifted to a nearby hospital to be treated for his injuries. (Dan Peled/AAP PHOTOS)

Police did not confirm the identities or ages of the people killed, nor did they speculate as to the cause of the incident.

"The crash is under investigation, we haven't determined any factors that have contributed to the crash at this stage, but certainly a crash of this nature, involving this many people is a very significant, very tragic incident for us," Superintendent Graeme Paine told reporters.

He acknowledged the "very significant impact and very significant consequences" of the crash, encouraging anyone not coping well with the trauma to access support.

"A crash like this is very, very confronting, and the first responders and the community members on scene at the time have done a very significant job in trying to help those who are injured and safeguard the scene and try and assist those who need medical attention," he said.

"This is an incident which impacts people, and it will not just impact those that are immediately involved in the incident, but also those that have helped, and also the local community and extends through to the family members involved."

The bus was heading to Townsville, around 1.5 hours from where the crash took place.

The Bruce Highway is closed in both directions and is experiencing significant delays, with police urging people to avoid the area.

Supt Paine wouldn't speculate when asked if fatigue was a factor in the crash.

"It's in the early stages of the investigation and I'm not going to speculate as to a cause," he said.

"There'll be a number of investigative avenues pursued to try and determine actually what happened."