At least four people are dead after a high-speed train came off the rails in Hertfordshire today.

Nineteen people were seriously injured and there were 80 walking wounded after the 12.10pm London King's Cross to Leeds GNER service became derailed near Hatfield.

Several coaches were derailed and the buffet car is lying on its side after the 115mph accident at 12.24pm.

Police said there were four confirmed fatalities but other emergency service sources said at least one more person was feared dead.

There were about 100 passengers on the train, which became derailed 300 yards south of Hatfield station. No other trains were involved.

The engine and the first two coaches remained upright but other coaches, including the buffet car, were derailed.

A Channel Four News reporter, Justin Rowlatt, who was a passenger on the train, described how it came off the rails and skidded along gravel at the side of the tracks.

He said: "The roof has been completely ripped off the restaurant car. The first class carriages have completely come off the rails.

"The carriages at the back of the train looked like they were whipping around and have gone into some of the supports for the electric rails."

Stephen Morgan, another passenger, said: "I just heard a big bang and then just everything went - the train went over on its side.

"A couple of carriages went over. I grabbed the nearest thing I could grab to get myself a little bit of comfort, and luckily enough I came through all right.

"The door was on its side so we managed to get that open to get some air in there in case there was any fire."

Asked what it was like in the immediate aftermath he replied: "Mayhem. The only thing I could say is mayhem ... there were ladies crying and everything."

A police spokesman said: "A search of the carriages has been completed and there is no one else trapped now.

"It is now a matter of getting people who need treatment to hospital and helping others at the scene."

Railtrack spokesman Phil Heath said the train "was on the correct line, and the signalling equipment appeared to have been working normally. It is very difficult for me to say what has gone wrong."

Superintendent Andy Wright, of Hertfordshire Police, said the train driver had not been hurt.

He said it was too early to speculate on the cause of the accident.