A major incident - which has now been stood down - was declared on Tuesday morning and saw a "significant number" of police, fire and ambulance crews sent to the scene in Bridgwater.

Giving an update on the situation, Inspector Rebecca Wells-Cole said 54 patients were triaged by paramedics and 26 were treated as "walking wounded".

She added that "a number" of people have been taken to hospital, but it was too early to confirm if any of their injuries were life-threatening.

No fatalities have been recorded.

The bus was taking workers to Hinkley Point C nuclear power station at the time of the incident, which also involved a motorcyclist.

A total of 70 members of staff were on board when it overturned, as well as the bus driver, Insp Wells-Cole added.

"It may take us some time to recover the bus and to clear debris from the road," she warned.

"I would like to take this opportunity to advise the residents to only travel where absolutely essential due to the icy road conditions caused by the cold temperatures overnight and the excess water on the roads."

'Crashing, screaming, shouting'

One woman, who lives nearby, told Sky News the road is known for being covered in surface water, and "it was only a matter of time before a serious accident was going to happen".

Charis Ware said: "I heard lots of banging, crashing, screaming, shouting. I had a feeling what had happened.

"I guessed it was an accident, purely because there's always surface water on that road. It's very scary.

"We have the same problem year after year."

Somerset Passenger Solutions, which operates the bus service, said an investigation into the "root cause of the accident" is now under way, and it is working closely with emergency services.

"We are supporting our colleagues and passengers who were involved in the incident," it said in a statement.

Avon and Somerset Police said officers were called at around 6am to the A39 Quantock Road following a "road-related incident involving a double-decker bus and a motorcyclist".

"Closures are in place at the junction of Sandford Hill and Quantock Road," it said in a statement.

Police warned of 'extremely icy' conditions earlier

The A39 is a major thoroughfare around the Quantocks - linking the M5 with places like Minehead and Exmoor - and is also a key road for people who work at the nuclear power station.

However, Hinkley Point C has said travel to and from the site has now been suspended.

Confirming paramedics were dealing with the incident, Southwestern Ambulance Service advised drivers to find alternative routes and "take care" while travelling due to roads being icy.

Avon and Somerset Police had earlier warned about the "extremely icy and dangerous" conditions following freezing temperatures after receiving more than 100 reports of road-related incidents in five hours.

A total of 53 crashes were reported to the force between 6pm and 11pm on Monday, and injuries were recorded in seven of them.