Police are waiting to question the driver of a coach which overturned on a motorway services slip road, seriously injuring six people.
The National Express coach clipped a kerb before careering into a lamppost and then rolling over as it entered Newport Pagnell services, Bucks.
The driver was breath-tested at the scene and arrested on suspicion of drink-driving and dangerous driving.
Thirty people were hurt, and six including the driver, went to hospital.
Police and four ambulances went to the scene on Monday afternoon.
Emergency services said most of the 30 were "walking wounded" with minor injuries.
The driver had to be cut free from the wreckage and police are hoping to question him today.
Thames Valley Police confirmed there had been 33 people on the coach.
The bus had left Birmingham at 1400 BST bound for Stansted and Luton Airport.