A woman and teenage girl were fighting for their lives last night, following the crash in Manchester. A man from Belfast was also treated in hospital for injuries.
The minibus, a hotel courtesy taxi, was on its way to Manchester Airport with passengers looking forward to flying out for their summer holidays.
The cause of the M56 crash, which ripped the roof from the Leyland DAF minibus, is not yet known.
Suitcases and other debris were strewn across the motorway. Police were trying to get in touch with relatives of the dead and injured.
Police said the driver was from Manchester and the other 14 passengers were in five different groups.
The parties on board were from Herefordshire, Fife, Belfast, Leeds and Tyne and Wear.
Two of the bus’s passengers, a woman and a teenage girl, remain in a critical condition in hospital after the early morning smash on the M56 two miles from Manchester Airport.
It was not known if the parties on board are families and no further details were given by Greater Manchester Police.
When emergency services arrived, there were seven people dead at the scene, police said.
Ian Bailey of the Greater Manchester Fire Service said it was a “particularly harrowing scene”.
Ambulance service spokesman Derek Cartwright described it as “utter carnage”, with debris spread across the motorway.
He said: “It’s quite a scene. I have to say there are probably 60 or so emergency personnel on scene here and there is a silence amongst people.
“It is a very, very difficult experience for people to take in.”
The white minibus appeared to have hit the central reservation of the busy motorway in several places.
Its roof could be seen embedded in the safety barrier, several yards behind the spot where the minibus came to rest. Police officers arrived at the scene almost immediately as a patrol car was on a ramp just yards from the stretch of motorway where the accident happened.
Emergency service workers began giving first aid, assisted by a passing male nurse who had stopped to help.
The crash involved the minibus, which was towing a luggage trailer, and three other vehicles and happened at around 5.40am.
None of the seriously injured were thought to have been travelling in the other three vehicles involved, although one of the cars was severely damaged.
A spokeswoman for Greater Manchester Police said accident investigators were working at the scene, around 400 yards from Junction 4 of the M56.
The two more seriously injured passengers were rushed to Wythenshawe Hospital. The remaining six people were not so badly injured and taken to local hospitals for treatment.
It is thought three of those have since been released following treatment at Wythenshawe Hospital.
Brendan Ryan, spokesman for Wythenshawe Hospital, said he had spent most of the morning at the scene helping the emergency services deal with the incident which he described as “extremely nasty”.
Outside the hospital, he said: “We have received three casualties at the hospital here, two of whom are critically injured and one of whom is stable.
“The two critically injured are being assessed and treated.
“It is difficult to put accidents on a scale, but certainly it was an extremely nasty event with a sizeable number of injuries.”