In total ten people — all spectators — were hurt in the accident on the first day of the endurance race, with eight others suffering less serious injuries.
“The joint resources of the organization and local forces have taken over and evacuated four injured, including two seriously affected,” organisers said in a statement early Sunday.
“Police have indicated that six more lightly injured have been transferred to hospital.”
The incident, which involved the Mini of Chinese driver Guo Meiling, saw the prologue — which takes place before the first stage Sunday — “neutralised” and immediately suspended in horrific scenes, race organisers said.
Guo’s car veered off the course at the 6.6-kilometer mark of the 11-kilometer prologue on a stretch of straight country road near Arrecifes, a small town 200 kilometers (120 miles) from the Argentine capital Buenos Aires.
Race chiefs immediately deployed four medical helicopters, three medical vehicles belonging to the organisers and eight local ambulances to the scene of the accident.
A 34-year-old man and his son aged 10 were the two most serious cases and had to be rushed to hospital with one suffering head injuries and the other chest trauma, said race director Etienne Lavigne.
“In total, we had 10 patients, including four children and one pregnant woman, who is ok,” said Daniel Modesto, head of the local hospital.
The accident left Guo’s car battered, its bonnet strewn on the ground, as emergency workers carted the injured off on stretchers.
Between 50,000 and 60,000 people were expected along the route of the prologue.
In 2015, Polish motorbike rider Michal Hernik died at the end of a stage, but the last accident involving spectators at the Dakar Rally was in 2011, when one person was killed.