Police are appealing for witnesses to this morning's six-vehicle pile-up at the Thickthorn roundabout.

The sliproad from the A47 was still closed to traffic from the Dereham direction at noon as road traffic officers launched an investigation into the crash.

It is believed at least six people were taken to Norfolk and Norwich University Hospital with injuries, some thought to be serious.

However, drivers who walked away from the crash scene were relieved to have escaped unscathed.

Dr Maria Martinez, who lives near Dereham, was taking her sons to school in Norwich and recalled the 'surreal moment' she saw a car flying over the back of theirs.

She and her sons escaped with nothing worse than shock but their Audi was left as a write-off.

Firefighters had to cut the roof off a Toyota Land Cruiser to free the driver while a Volkswagen Polo was crushed front and back.

Sgt Dave Cartwright said it appeared from witness statements that the Land Cruiser had gone out of control in some way leading to the pile-up. He appealed to any further witnesses to make contact so they could work out what had happened.

The Thickthorn roundabout on the outskirts of Norwich is now clear following a serious pile-up at about 8am. The accident, involving at least six or seven vehicles, occurred on the A47 slip road from the Dereham direction.

Eye witness Mark Nicholls said: 'I was on a bus which got stuck and we had to get off. It looks as though a vehicle has ploughed into the back of a stationary queue of traffic at quite high speed.

'There is a vehicle on its side and others badly crushed at the front and back.'

He said at the time he got off the bus emergency services had yet to arrive and passers-by were helping people trapped in their cars.

A police spokesman said ambulances had been called to the scene.

The crash was causing serious tailbacks on the A47 from the Dereham direction but was clear by 10.30am.