The sound was caused by a four-wheel-drive, which had been set alight in the park. 

A witness told the Central Western Daily he ran out of his home and saw firefighters battle to extinguish the fire.

"We saw people walking about with yellow safety vests/coats on, then noticed flames rising and thought at first it was a house fire, then we heard a couple of small explosions," he said. 

"That may have been either the fuel tank or tyres, so I drove around and found it to be a 4x4 on fire with fire brigade personal in action."

If you have photos or video footage of the explosion and fire email them to nicole.kuter@fairfaxmedia.com.au