A man was shot and critically injured at a pro-Kurdish rally in a Stockholm suburb at the weekend, police said on Sunday.
Organizers of the event said the incident in the suburb of Fittja on Saturday had a "political motive" but did not elaborate.
Local media reported that the victim, described by the Svenska Dagbladet newspaper as a 52-year-old Kurdish man, was in a minibus covered in Kurdish flags that was following the march when he was shot. Witnesses said the assailant fled the scene by car.
"This is a direct attack against the protesters, against the Kurds," one of the rally organizers was quoted as saying by Swedish news agency TT.
Sweden's security service Säpo has been asked to investigate the shooting and suggested on Sunday that the violence was likely linked to the protest.
"We started knocking on doors last night and will continue to do so," Carina Skagerlind, a spokeswoman for Stockholm police, added on Monday.
She confirmed that no-one had been arrested and said that officers had so far failed to find the getaway car.
There are about 170,000 Kurds in Sweden, which has a total population of 9.8 million.