Police are looking for a man who crashed a stolen front-end loader into a pub in Adelaide early this morning.

Key points: The Valley Inn is closed until further notice and investigators are on the scene

The Valley Inn is closed until further notice and investigators are on the scene Police are also investigating a hold-up at the Exeter Hotel overnight

Police are also investigating a hold-up at the Exeter Hotel overnight A man stole cash and the contents of a staff member's purse before leaving through a rear door

Police said the man crashed the vehicle into the Valley Inn on Grand Junction Road, Hope Valley, at about 5:00am, causing extensive damage to an office and smokers' area next to the gaming room at the back of the building.

He then drove through the back fence of the property and dumped the vehicle about 200 metres south on Leeds Avenue.

Witnesses saw the man leave the truck on foot, heading towards Valley Road.

No-one was injured in the incident, and crime scene investigators are on the scene.

The hotel is closed until further notice.

"Police are just asking anyone with information who may have seen anything to contact Crime Stoppers on 1800 333 000," Senior Constable Peta Scholz said.

Hotel worker Anishma Nepal Chalise said the attack was scary.

"When I came and saw from that door, there was a big truck smashing the wall, that's what I saw," she said.

Sorry, this video has expired The front-end loader was caught on CCTV on its way to the pub.

Vehicle stolen from quarry

The front-end loader was hot-wired and stolen from a quarry on Hancock Road in Golden Grove.

Company owner Richard Fricker described the events as "madness".

"You wonder what that person was thinking, whether they had a grudge against the hotel, it's about 7 kilometres," he said.

Damage to the gates of the quarry that the front-end loader was stolen from. ( ABC News )

"It's not exactly an easy thing to steal a loader, they've got to go through two locked gates to get it on the road and drive it down there.

"They must have had a lot of energy — or hate."

Mr Fricker said the thief had smashed through two gates, causing up to $10,000 damage, although he said the stolen loader appeared to be in relatively good condition.

The owners of the Valley Inn declined to comment to the ABC.

Man held up Exeter Hotel with baseball bat and knife

Separately, police are also investigating a hold-up at the Exeter Hotel overnight.

Police said a man armed with a knife and a baseball bat and wearing a skull mask threatened staff in the gaming room of the Semaphore Road pub just before midnight.

He stole cash and the contents of a staff member's purse before leaving through a rear door.

One of the staff members was hit with the bat during the robbery and was treated at the scene by paramedics.

The suspect is described as about 190 centimetres tall, with a slim build, wearing full length white overalls, dark shoes and a skull mask.

Police searched the area with the assistance of a police dog, which lost the scent in Young Street.