A man is missing after his truck caught fire and blew up while carrying a haul of explosives in Western Australia's Mid West region.

Key points: A search is underway for Tony Hickey after his truck exploded near Sandstone

A search is underway for Tony Hickey after his truck exploded near Sandstone Police say they could not find him near the scene and they are very concerned for him

Police say they could not find him near the scene and they are very concerned for him Forensic officers are examining the truck to try to confirm what caused it to explode

Driver Tony Hickey's truck was discovered on fire between Sandstone and Menzies, on the Sandstone-Menzies Road, about 5:00pm yesterday after apparently exploding.

Police attended the scene, about 40 kilometres south of the town of Sandstone and around 700km north-east of Perth, but 67-year-old Mr Hickey was nowhere to be found.

"A search of the area did not locate Mr Hickey and, given the remote area and the explosion, police are very concerned for his welfare," WA Police Inspector Dean Snashall said.

"It was established that Mr Hickey was driving this truck which at the time was carrying a quantity of explosives.

For unknown reasons the truck appears to have caught fire and exploded and upon police attendance Mr Hickey was not located in the truck.

Roads were closed in the area last night while the scene was cleaned up.

Specialist forensic officers from Perth are at the scene this morning to investigate the cause of the explosion.

Police said they were treating Mr Hickey's disappearance as a missing persons probe and would continue the search for him throughout the weekend.

Investigators would like to hear from anyone travelling in the area that may have seen or even picked up the truck driver.