9News obtained footage of the moment the firebug struck about 4am today, before making a run for it.

The van was outside a panel beating business in Nerang when it went up in flames.

“It just went off like a bomb, blew all the glass out,” witness Matt Spears told 9News.

“[It] blew the window 10 metres that way, luckily there was no other cars around.”

The witness told 9News a man staying nearby attempted to confront the arsonist.

Footage captured the bystander yelling, “Are you gonna run you little dog?”

“A young fella was staying up in the next shop,” Spears said.

“He yelled out, ‘What are you doing, mate? What are you doing?’ and [the alleged arsonist] said ‘what’s it look like?'”

“Then boom, he threw the thing in there and it all went up.”

Police say the firebomber fled on foot and was last seen at Glennon Park, about 400 metres away from the crime scene.