STOCKHOLM (AFP) - A car explosion outside the southwestern Swedish city of Gothenburg on Friday evening has left four dead, police said Saturday.
The explosion took place as the car with four passengers entered a roundabout.
Police have not determined the cause of the blast nor released details of the victims' identities.
"Three people travelling in the car died during Friday evening," Gothenburg police said in a statement.
"A young girl taken to the hospital with life-threatening injuries died during the night."
Emergency services said the car was "practically demolished".
An eyewitness driving on the roundabout at the time of the explosion told public broadcaster SVT that pieces of the vehicle shot into the air shortly before 1530 GMT.
"When I came up to the car I saw that it must have been a bomb. It was completely torn apart, the front part of the engine and everything was gone," said Janne Wolltin, who said another driver from the roundabout had begun dousing the flames when he arrived.
Local media reports identified one of the victims as a well-known criminal gang leader in the city that has seen tit-for-tat revenge killings between rival groups for several years.
In March, gunmen sprayed a pub in the city with bullets, killing two people and injuring more than 10 in a suspected retribution attack.
Robert Karlsson, head of the region's criminal investigation unit, said it was too early to say if the explosion was connected to the gang conflict and that all of the victims had yet to be identified.
"We have no leads, either in one direction or another. We are just at the beginning of this," he told public broadcaster SR.
Police have opened a criminal investigation after the incident into suspected explosives or flammable goods offences.