A DELICATE operation has taken place to free a double-decker bus that became wedged under an overpass roof.

The Arriva bus crashed into part of the Cornmill shopping centre, in Darlington, at about 4pm, causing delays for motorists.

Eyewitnesses talked of hearing a large bang at the point of impact.

Large vehicles have a clearance of a little more than four metres at the tunnel area.

The driver of the bus, who did not wish to be named, told The Northern Echo that there were no passengers on board the bus at the time of the collision.

No one was hurt, although police officers attended the scene to direct traffic and help free the vehicle.

The bus, Arriva's 1B service from Darlington to Tow Law, was immediately taken out of service after the incident.

The incident, which happened on a stretch of road in Darlington town centre that is mainly used by buses and taxis, led to bus services being re-routed while Arriva engineers worked to release the vehicle.

An HGV company with specialist expertise in freeing trapped vehicle was called to remove the bus, which was gingerly dragged from where it had become stuck.

The operation to free it took about 45 minutes and attracted dozens of onlookers.

An Arriva engineer at the scene, who did not want to be named, said letting down the tyres of the bus would not help to free it.

This is because letting down the tyres would result in the vehicle's suspension being raised, nullifying any benefit of air removal from the wheels.

The bus sustained cracks to its upper deck front window, and the left side rear wheel was raised completeley from the ground.

However, the engineer said there was no risk of the vehicle being written off, saying the damage was "superficial".

A spokeswoman for Arriva said an investigation into the cause of the collision would begin shortly.