The accident occurred around 5am on Sunday morning, in the village of Vollsjö, northeast of Sjöbo in southern Sweden.
“The car skidded for a long way, and then crashed heavily into some trees with its right side. The car then fell back onto the road,” Claes Jeppsson, who was head of the on-site rescue operations, said to local newspaper Skånska Dagbladet.
When emergency services arrived, three of the four young men were lying outside the car, and the fourth was taken out of the car by rescue staff.
The injured men are all between the ages of 15 and 21, according to local police. All were severely injured in the accident.
Two of them have been taken to Skåne University Hospital in Malmö, and two to Lund.
“The outcome is uncertain for the two teenagers in Lund,” said Ystad police officer Pia Eldh to news agency TT.