A powerful firework is though to have damaged the van

The blast happened just after 0400 BST on Tuesday at Goldthorpe police station causing the doors and windows to be blown out.

Fragments of a firework were found inside the community support van which had been parked next to a wall.

The area was sealed off and police are unaware of a motive for the attack.

Fingertip search

Insp Mark Spooner said it is believed to have been a large firework to have caused so much damage.

He said: "We know now that it was some sort of firework-type device, but obviously it's early days and inquiries are still continuing into whether it was placed inside another object or it was a firework on its own."

"Like any police station, vehicles are from time to time damaged by members of the public, but this is obviously something much more serious than that.

"Explosives by their nature are clearly very dangerous and it clearly could have been much worse."

It is thought the police station was unoccupied at the time of the blast, and the alarm was raised after a member of the public heard a loud bang.

An extensive search of the area was carried out by about 12 officers, many on their hands and knees.

The incident follows a firework attack on a house three miles away in Thurnscoe on Sunday, where a firework was put in a beer can in an open window.

The explosion blew out the window of a downstairs games room and caused damage inside.