A female crash casualty remained in a critical but stable condition in hospital yesterday following the serious collision between a coach carrying schoolchildren on a field trip and car on the A11 at Elveden on Friday.

The woman was airlifted to Addenbrooke's in Cambridge after the black Mercedes she was travelling in collided with a white Scania coach carrying 48 people, mostly teenagers, from Oaks Park High School in Ilford who were returning home to London following a field trip in Norfolk.

A further eight people were taken to hospital, including five schoolchildren aged 14 and 15 from the coach who were treated for bumps and bruises at West Suffolk Hospital in Bury St Edmunds following the 1.24pm crash, but have since been discharged.

The other three casualties were women who had also travelled in the Mercedes from London, one of whom was taken to the Norfolk and Norwich University Hospital and the other two airlifted to Addenbrooke's.

The crash, near the war memorial between the A1101 roundabout and B1106 junction, also left the other 43 coach passengers 'walking wounded' and closed the notorious traffic bottleneck for six hours, leaving motorists facing long diversions and huge tailbacks.

The usual rush hour traffic on the busy single carriageway, where dualling work is set to start early next year, was swelled by holidaymakers and music fans heading to Thetford Forest for a concert by classical tenor Alfie Boe.

On Friday, South West Norfolk MP Elizabeth Truss said she would be writing to roads minister Mike Penning in the light of the crash to ask for a precise date from the Department for Transport for when the dualling work will start.

Sgt Bob Patterson, of Suffolk Police serious collision investigation team, said the cause of the crash was still being investigated, but the said the collision between the coach, operated by a Milton Keynes firm and car was a 'head on impact.'

However, he said the weather conditions were not a factor as it was bright and sunny at the time of the incident.

Anyone who witnessed the crash is asked to contact Suffolk Police on 101.