Townsville police have declared an emergency declaration under the Public Safety Preservation Act, due to a truck rollover along the Flinders Highway at Pentland, west of Charters Towers.
The declaration was made just before 9am with an exclusion zone encompassing two kilometres around the crash site, near the Warrigal Creek.
As of 10:30am, there were three Queensland Fire crews on scene.
A Queensland Fire Department spokesperson says a semi-trailer carrying fuel has flipped, spilling a large amount of diesel onto the road.
Traffic has been stopped in both directions.
Heavy haulers have been called in to remove the vehicle, and work is underway to mop up the spill.
Motorists and other members of the public are advised to avoid the area, and those within the exclusion zone are asked to remain indoors until further notice.