At least 10 people were arrested in southern Sweden and several police officers were injured in violence which broke out after an anti-Muslim Danish politician was blocked from attending a Quran-burning rally, police said Saturday.
Protesters threw stones at police and burned tyres on the streets of Malmo late Friday, with violence escalating as the evening wore on, according to police and local media.
The demonstration of about 300 people was connected to an incident earlier in the day in which protesters burned a copy of the Islamic holy book, police spokesman Rickard Lundqvist told Swedish tabloid Expressen.
Between 10 and 20 protesters were arrested late Friday and "have all been released," police spokesman Patric Fors told AFP.
The violence had subsided by Saturday morning.
Rasmus Paludan, who leads the far-right Danish anti-immigration party Hard Line, was due to travel to Malmo to speak at Friday's event, which was being held on the same day as weekly prayers for the Muslim sabbath.
But authorities pre-empted Paludan's arrival by announcing he had been banned from entering Sweden for two years. He was later arrested near Malmo.
"We suspect that he was going to break the law in Sweden," Calle Persson, spokesman for the police in Malmo told AFP.
"There was also a risk that his behaviour... would pose a threat to society."
But his supporters went ahead with the rally, during which six people were arrested for inciting racial hatred.
Paludan later put up a scathing message on Facebook.
"Sent back and banned from Sweden for two years. However, rapists and murderers are always welcome!" he wrote.
Paludan last year attracted media attention for burning a Koran wrapped in bacon -- a meat that is anathema for Muslims.