A Toyota and a Seat car were involved in a collision at around 9.40pm.
It happened on the on the A630 at Conisbrough, approximately 600 metres from Archer Way when travelling towards Doncaster.
Two men and a woman inside the Toyota have died. Another two people inside the same car, a man and a woman, have been taken to hospital with serious, life-threatening injuries.
The man driving the Seat has also been taken to hospital with serious injuries, though his injuries are not currently believed to be life-threatening.
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The road is closed while police are at the scene and it’s anticipated it will remain closed for a further couple of hours.