Western Australian police have sealed off part of the Geraldton city centre in Western Australia's mid-west after a man was seriously injured overnight.
Police are investigating on the streets of Geraldton. (ABC Midwest Wheatbelt: Piper Duffy)
Police said the man, in his 40s, was found lying on the ground on Darlacher Street at about 10.15pm.
ABC understands his injuries were the result of a fight.
He suffered serious injuries and was taken by ambulance to Geraldton Regional Hospital before being airlifted to Royal Perth Hospital as priority number one this morning.
An RPH spokesman said the man was in a critical but stable condition.
Motorists and pedestrians are being asked to avoid the area. (ABC Midwest Wheatbelt: Piper Duffy)
As part of the investigation, parts of Marine Terrace and Durlacher Street were closed for several hours, preventing local businesses, including cafes and libraries, from opening.
Motorists have also been advised to avoid the area.
Detectives are appealing for anyone with information about the incident to contact Crime Stoppers on 1800 333 000.
