Riots have broken out across the country in recent days after Danish far-right politician Rasmus Paludan planned to carry out Koran burnings in various towns and cities.
On Sunday, a crowd of about 150 people threw stones at police officers and set fire to cars in the eastern city of Norrkoping.
Mr Paludan and his Stram Kurs party had organised a demonstration in the area but never showed up, Swedish media reported.
Police responded to the protest by firing warning shots, but three people were “hit by ricochets” and taken to hospital.
They were later “arrested on suspicion of crime,” police said.
Unrest was also reported in the nearby city of Linkoping, where Mr Paludan had planned to hold a demonstration but he later cancelled.
On Facebook, the politician said he made the decision because Swedish authorities were “completely incapable” of protecting him or themselves.
Over the past three days, violent clashes have been seen in Sweden’s capital city, Stockholm, as well as a number of other cities.
A dozen police officers were injured and four emergency vehicles were set alight in the central city of Orebro after riots broke out on Friday, due to Mr Paludan’s plan to burn a Koran there.
In the southern Swedish region of Landskrona, some protesters set cars, tyres, and bins on fire, while others erected a barrier to obstruct traffic.
Similar demonstrations took place in the country’s third-largest city, Malmo, which saw a city bus and other objects set alight.
Mr Paludan set up the Stram Kurs party in 2017 and it is now known for its anti-immigration and anti-Islam agenda