A SIX-YEAR-OLD boy is in a Brisbane hospital with a suspected fractured skull and four other people have been injured following a mystery motorbike crash on private property in Childers.
Childers Police Senior Constable Donna Gay said it was believed two unregistered trail bikes collided on a Wyatts Rd property late Sunday afternoon.
Snr Const Gay said an 18-year-old man riding one of the bikes was injured, along with his passenger, the six-year-old boy.
A 26-year-old woman and her six-year-old boy passenger were also injured.
A third rider, a 23-year-old man, also suffered a suspected fractured ankle.
It is believed none of the people involved in the crash was wearing a helmet, and police also suspect a third bike was involved in the incident.
Snr Const Gay said one of the children received a broken leg and the other suffered serious head injuries.
"Queensland Ambulance Service was not called to the crash," she said.
She said the five injured people were taken to Childers Hospital in a private vehicle.
"A 31-year-old witness and the female rider refused to answer questions (about the crash)," Snr Const Gay said.
A Queensland Health spokeswoman said the six-year-old boy was transferred to Bundaberg Hospital with serious head injuries, but was flown to Royal Brisbane and Women's Hospital late Sunday night.
Bundaberg Police Acting Inspector Erwin Hoffmann said investigations were continuing to determine what happened on the property.
Acting Insp Hoffmann said the crash served as a timely reminder to motorbike riders.
"If you have a crash, at the end of the day it makes no difference if it was on a road or in the bush," he said.
Acting Insp Hoffmann said people riding motorbikes should always be dressed in protective clothing and wearing a helmet at all times.