The National Express coach - the 777 Birmingham to Stansted service - overturned in the car park of the south bound service area at 4pm today.

Five of the casualties are described as 'seriously injured' and two were taken to hospital by air ambulance. A total of 30 were injured.

The driver, who was physically trapped inside, was released by firefighters within an hour of the crash. It is understood that he was conscious.

Eyewitness Raj Bagna said: "I just pulled up for a cup of coffee and I saw this coach on its side.

"People were smashing all the windows to get people out. There was blood everywhere.

"Passengers had injuries to their heads, arms and legs.

"The driver was still stuck in his seat by the steering wheel. I was trying to cut the steering wheel off.

"His feet were crumpled up and the fire brigade came over to take over. He was not as bady as some of the other passengers."

Milton Keynes General Hospital was prepared for the 'major incident' as a steady stream of ambulances were seen bringing in casualties.

Police had sealed off the approach road to the Accident and Emergency Department.

The bus had been seen heading towards the car park for a scheduled stop before striking a high kerb, flipping over and landing on the driver's side of the vehicle.

The coach then struck a tree and a lamp post.

Builders Dean Dallison and James Brady were having a coffee in their van when they heard a screech of tyres and then a very loud bang.

The pair then ran forward and used a fire extinguisher and a nearby litter bin to smash through the side window to rescue a crying girl and a woman.

Welcome Break staff were among the first to help the casualties, providing them with first aid and refreshments.

The number of injured people has not yet been confirmed. There are four ambulances, two fire engines and six police cars at the scene.

The M1 has not been affected by the crash although the southbound services are shut.

If you saw the crash or have any photographs please contact the Citizen news room on 01908 372279 or click here.