A nine-year-old girl has died after the mobility scooter she was riding ran off a dirt road north-west of Brisbane.

Police are investigating the accident which happened at Laceys Creek about 2:00pm on Thursday.

It is believed the girl was riding the mobility scooter with a four-year-old boy on Raynbird Creek Road.

The scooter left the dirt road and crashed into a culvert.

The girl was pronounced dead at the scene while the boy was taken to Royal Brisbane and Women’s Hospital with non life threatening injuries.

Queensland’s police forensic crash unit is investigating the accident.