The smash happened at the intersection with Ross Camp Road in South Isis, 57 kilometres south of Bundaberg, about 1pm on Friday, leaving two dead and two injured.

Netball Queensland confirmed the young crash victim was due to participate in the 2018 Primary Schools Cup being held in Bundaberg this weekend when tragedy struck.

"We are heartbroken that two people have tragically lost their lives, and others were seriously injured, in this accident," Netball Queensland said in a statement.

"Our deepest sympathies go out to the families of those involved in the incident. Due to the sensitive circumstances of this incident, we ask that you please respect the privacy of the family and school community at this time.

"The entire netball community will be devastated by these events and our focus at this difficult time is to provide support for our netball and school communities.

"We want to thank and acknowledge the police and emergency services personnel for their role in today’s events and who will no doubt be impacted by these tragic circumstances. For your bravery, professionalism and support we say thank you on behalf of our community.

"The Department of Education has provided support to the school, and additional support services will be provided at the event by the Bundaberg Regional Council."

The young girl, who was a passenger in one of the cars, as well as the 52-year-old male driver of the other car, were declared dead at the scene.

The Bundaberg and Sunshine Coast RACQ LifeFlight Rescue helicopters flew two injured patients, believed to be the eight-year-old girl's family, to Sunshine Coast University Hospital.

The Sunshine Coast helicopter airlifted a woman in a critical condition after she suffered upper limb and chest injuries. The Bundaberg helicopter airlifted her another young girl who had also suffered upper limb injuries, but was in a stable condition.

The Bruce Highway remained closed into Friday evening as the Forensic Crash Unit investigated.