Three of the six victims killed when a bin lorry careered out of control through a city centre were an elderly couple and their grand-daughter. A primary school teacher and two women in their 50s also died.

Jack Sweeney, 68, his wife Lorraine, 69, and grand-daughter Erin McQuade, 18, all from Dumbarton, died after the council vehicle drove through a street full of shoppers in Glasgow.

The other victims were named as Stephenie Tait, 29, a primary teacher from Glasgow, Gillian Ewing, 52, from Edinburgh, and Jacqueline Morton, 51, from Glasgow.

Police said that of the 10 injured, four have been discharged and six are currently receiving treatment for their injuries, including the driver of the lorry. Four patients remain in Glasgow Royal Infirmary. One is expected to be discharged later today, one  is in a critical condition, one patient is serious but stable, and one patient is stable.

A further patient who is being treated at the Western Infirmary is in a stable condition. The sixth patient, who is being treated at the Southern General Hospital, is expected to be discharged later today.

Mr Sweeney was a former president of Bramalea Celtic supporters club in Canada. A statement posted on the supporters club Facebook page said: "It is with great shock and sadness we share with you our friend and past president Jack Sweeney, his wife Lorraine and granddaughter Erin were victims of today's tragedy in Glasgow.

"Our thoughts and prayers go to the family and friends of the Sweeney family."

Relative John Sweeney described himself as ''feeling heartbroken'' on Facebook. He wrote: ''No words can describe the pain. RIP Jack, Lorraine and Erin. Thoughts and prayers go out to the other families that lost loved ones as well.''

Miss McQuade was a a first-year student of English literature at Glasgow University and also worked at the Cameron House Hotel on the banks of Loch Lomond. The hotel said in a statement: "We are saddened to hear we have lost one of our brightest and dedicated members of housekeeping staff, Erin McQuade.

"We want to offer our deepest condolences and sympathies to the family of Erin and to all those who have been affected by the tragic events at George Square yesterday."

Celtic chief executive Peter Lawwell said: "We would like to send our deepest condolences to everyone affected by yesterday's tragedy in Glasgow city centre.

"We know of Jack Sweeney's strong connection to Celtic, as someone who gave so much to the club. I am sure I speak for everyone connected to the club when I say that our sincere thoughts and prayers are with them all, with their relatives and with every other victim of this tragic incident."

Celtic will hold a minute's silence before Saturday's home game with Ross County. Other Scottish football clubs are also expected to pay their respects.

Rangers said in a tweet: "Everyone shocked and saddened to hear about the tragic incident at George Square yesterday."

Ms Tait was a teacher at St Philomena's Primary in Royston.  Catherine Gallagher, head teacher, said: "The entire school community is deeply saddened by this tragic news.Stephenie was an excellent young teacher, dedicated to the children.  Our thoughts and prayers are with her family and friends at this time.

"We will be supporting colleagues in every way possible. Stephenie made a wonderful contribution to the life of St Philomena's. She will be sadly missed by both pupils and staff."

Former pupils paid tribute on Twitter.  Liam Andres said: "Just found out that one of the dead was one of my teachers from primary school. Such horrible news,will be missed RIP miss Tait #georgesquare"

Marcia Mackay tweeted: "RIP miss tait was such a great teacher when I had her in primary rest in peace condolences to her family and friends".

Selina White added: "Absolutely gutted to hear one of my primary teachers was involved in that accident in George Square y/day. Rip Stephanie Tait."

Ms Tait had studied at Glasgow University, whose Principal Professor Anton Muscatelli said it was "deeply saddened" to learn of the death of one of its current students and a graduate.

He added: "Our thoughts and prayers are with the families of Stephenie Tait, who graduated in 2006, and Erin McQuade, a first-year student of English literature.

"This is an awful time for those concerned and for the wider university family."

First Minister Nicola Sturgeon said while 2014 had been an incredible year for the city , which hosted the Commonwealth Games in the summer , it had been ''bookended by two unimaginable tragedies'' (Clutha and the bin lorry crash).

She described Glasgow as a "city with a broken heart" but added: "This city will pull together to support those who have been affected, not just in the days ahead but in the weeks and months to come.''

It is thought the bin lorry driver might have fallen ill at the wheel as he travelled up Queen Street and his vehicle struck a pedestrian outside the Gallery of Modern Art.

The truck continued, hitting several other people and coming to a halt only when it crashed into the side of Millennium Hotel in George Square.

A Glasgow City Council spokeswoman said there were two other crew members on the lorry at the time of the crash, but the condition of the two men was not known.

Hundreds of floral tributes have been placed at the scene.

The Christmas lights have been switched off in George Square and flags on public buildings in the city are flying at half-mast.

Police have now removed the steel cordons which had been put up round the crash site and the roads around the square are now open again after the victims' bodies were removed by a fleet of private ambulances earlier this morning.

Chief Superintendent Andy Bates said: "This is a tragic incident which occurred in the heart of Glasgow city centre at a time when people were preparing for the festive season. My thoughts are with the family and friends of those involved.

"My officers will continue to work with partner agencies to investigate the cause of the incident. If anyone has any information that may assist our inquiries please contact Police Scotland on 101.

"I'm also aware that some members of the public may have video or images of the incident and it would be helpful if they could send them to georgesquareincident@scotland.pnn.police.uk."

He added that a report on the crash would be submitted to the procurator fiscal.