A man who allegedly stole a semi-trailer in New South Wales and led police on a 100 kilometre chase before ramming into parked cars, injuring eight people, has been charged with a raft of offences.

Rodney Johnson, 29, allegedly stole the truck from a service station at Murrurundi in the Hunter Valley while the driver was paying for fuel yesterday morning.

In vision obtained by 9NEWS, police deployed road spikes to stop the truck after it was allegedly sighted driving erratically about 100 kilometres south along the New England Highway towards Singleton.

The stolen truck collided with several cars before smashing into buildings and a pub. (Image: KOFM Newcastle‏) (KOFM Newcastle‏)

Hitting the spikes, the truck careered down George Street in Singleton for another two kilometres on shredded wheels, taking out cars and side-swiping buildings until it came to a flaming stop outside the Royal Hotel.

Johnson underwent a mental health assessment at Singleton Hospital before being taken in for police questioning and he's since been charged with numerous offences including stealing a motor vehicle, police pursuit, using an offensive weapon to prevent lawful detention and malicious damage.

He is expected to appear in court later today.

A bus shelter roof is torn off by the truck, which is still on fire. (Dan Irwin/Twitter) (Twitter / Dan Irwin)

The dramatic moment the truck driver is wrestled to the ground.

Daniel Storey, the manager of the Horse and Jockey Hotel, claimed the incident occurred just outside his establishment.

He said he was on the phone when he heard the screech of tyres and the sound of metal-on-metal.

"It was amazing no one was killed," Mr Storey said.

An emergency crew including seven ambulances and a Westpac rescue helicopter arrived to a “chaotic scene involving a number of quite distressed people”.

Eight people were assessed at the scene, with five taken to hospital.

“We treated four patients at the scene, including one 67-year-old male in a critical condition with head and chest injuries and a 62-year-old female with pelvic and hip injuries,” NSW Ambulance Inspector Luke Wiseman said.

A husband and wife were among those taken to John Hunter Hospital.

The stolen truck on fire, after it ploughed through the main road of Singleton.

The man has since being released while his wife remains in hospital but is expected to make a full recovery.

The removal of the wreckage was underway overnight and is expected to be cleared by the morning.

A critical incident team from Port Stephens Local Area Command will now investigate all circumstances surrounding the incident including the deployment of road spikes.

The truck crashed into a building and other vehicles.

The crash has caused smoke to billow across the town.