A road train carrying ammonium nitrate has been destroyed by fire near the West Australian Mid West town of Meekatharra, with police describing it as a "critical incident" and praising the actions of the driver.
Great Northern Highway was closed 110 kilometres north of the town for a short time overnight during the emergency.
Police said the truck with two trailers was "laden with" ammonium nitrate when it caught fire.
Ammonium nitrate is commonly used as a fertiliser in agriculture and as the main component in an explosive often used in the mining industry.
"The driver did a fantastic job getting the truck off the highway with the limited time he had, after discovering the fire in the rear cabin," Meekatharra Police Sergeant Greg Dowding said.
A 1-kilometre exclusion zone was put in place at the accident site, with motorists asked to avoid the area amid fears of an explosion.
The highway was briefly reopened before it was closed again by volunteer firefighters following discovery of "a hole in one of the road train's containers".
Shortly before 11:30pm, police announced the road had been reopened in both directions.
Meekatharra Police said the $400,000 prime mover had been "totally destroyed".
It is believed an electrical fault started the blaze in the cab of the truck, which was towing two trailers.
