Video has captured the moment a ute carrying gay cylinders exploded like a "bomb" after bursting into flames at a McDonald's drive-through in California.
The blast at the Coachella eatery on Saturday in the US was so powerful it blew the tailgate off the truck and spread flames to the roof of the restaurant,LA Weekly reports.
A witness told the Fox News she initially thought the explosion was caused by a bomb.
"Heaven forbid! But it was bad, the flames were shooting up," she said.
The fire started after the driver heard hissing noises coming from the back of the truck and went to inspect its load of propane cans.
When he moved one of the cans, it exploded in front of him and set off another cylinder nearby.
"The blast caused the roof of the truck to buckle and the tailgate to blow off, striking a vehicle behind it," the Riverside County Sheriff's Department said in a statement.
"The ensuing fire engulfed the truck, scorched part of the drive-through, and damaged the roof of the restaurant."
It is believed the explosion was sparked by static electricity.
The driver was admitted to hospital with second degree burns.
Three members of his family were also hospitalised with non-life threatening injuries.
Patrons were evacuated from the restaurant but were not injured.