Three spectators have been killed and two are in hospital with serious injuries after being hit by cars in two different crashes at the Jim Clark Rally.
The most serious incident took place at about 4.07pm when a Citroen came off the road at Little Swinton, colliding with four spectators.
Three of them – two males and one female – were pronounced dead at the scene. The fourth, a male, is in a critical condition in Edinburgh Royal Infirmary.
Two hours earlier, a car collided with five spectators at a different location on the Eccles stage of the rally. One of them, a man, was transferred to Edinburgh Royal Infirmary and is in intensive care.
Police Scotland abandoned the rally with immediate effect.
The fatal accident happened on the Swinton stage of the rally at Little Swinton near Coldstream, about half a mile west of Swinton village.
An air ambulance was called when the emergency services arrived.
It is understood a Citroen rally car left the narrow B road at speed and collided with spectators after crossing a small humpback bridge on what is locally referred to as Swinton House Road. The car ended up in a field.
A police spokesperson said the driver and co-driver are understood to be uninjured.
Earlier in the day, five spectators were also injured after being struck by a vehicle close to Crosshall Farm on the Eccles stage of the rally.
That incident occurred at 2.05pm when a car came off the road and collided with five spectators.
Four people were treated at the scene and one man was taken to Edinburgh Royal Infirmary, where he remains in intensive care.
Two males sustained fractures and were taken to Borders General Hospital. A male and a female sustained minor injuries.
Official confirmation of the crashes came almost seven hours after the first collision.
Superintendent Phil O’Kane said: “I’d like to offer my condolences from Police Scotland, Scottish Borders Council and the organisers of the Jim Clark Rally for the tragic circumstances that bring us here.”
He said the rally was cancelled after the fatal crash, and the Eccles stage was suspended after the first crash.
He was unable to give further details about the dead or injured spectators.
Questions remain about where people were standing and how the cars left the road.
Mr O’Kane said responsibility for safety rests with the rally’s organising committee.
“But I do know it is well stewarded, safety is a very big consideration in the planning of it,” he said.
Eyewitnesses to the fatal crash described “terrible” scenes.
Spectator Tony Cowan told the BBC: “It was just one car which lost control. It went sideways one way and then to the other side of the road and ploughed into four people.
“It was terrible, absolutely terrible. I ran to help but there was little I could do. The air ambulance arrived after about three quarters of an hour. There were police cars and ambulances. It was chaos, just chaos.”
Kirsty Nunn, 18, who had been at the rally from 2pm, said she was standing at a stage about a mile away from the accident site.
She said: “It was about 4.15pm the accident happened. We left after that as it was cancelled.
“At first there were yellow flags at the stage we were at asking the cars to slow down.
“The rally cars just kept going and after a while the cars were stopped and there weren’t any more coming.
“There were about 15 to 20 emergency service vehicles – there were a lot anyway.
“The stewards told the spectators there and they moved on. More emergency service vehicles were coming for 10 to 15 minutes.
“We got to our car to leave and we were stuck as the road was closed.
“The accident was 500 metres down the road from where we passed.
“There were mountains of vehicles with blue lights on and we couldn’t see any more.”
Another eyewitness wrote on Facebook: “Huge accident at rally. Not far from us. About 15 emergency vehicles here now and about 40 people stood working on the injured. Not good.”
Another spectator, Tommy Tait, wrote on Facebook: “We must be like cats have nine lives never have we been so close to getting wiped out by a rally car our thoughts go out to the 4 who got hit.”
Others on social media had earlier posted pictures and comments about the rally.
One person commented on “brave” people sitting on a verge close to a junction at Eccles.
Scores of others left messages of condolence on the Jim Clark Rally website.
Scotland’s First Minister Alex Salmond said: “This is desperately sad and difficult news from the Borders of the tragic circumstances that have occurred at the Jim Clark Rally.
A spokesman for the event organisers said: “Naturally we support the decision to cancel the event, and more importantly our thoughts are with the friends and families of the people tragically killed and injured in today’s incident.”
The motorsport event, the biggest of its kind in Britain, takes place annually over three days on closed roads in the Duns and Kelso areas.
The rally is named after Formula 1 driver Jim Clark, who grew up in the area.