"Our preliminary reports indicate that three police officers were injured, but not seriously," Towe Hägg from Stockholm police told AFP. She did not know how the injuries occurred.
About 100 members of the neo-Nazi Party of the Swedes had gathered Saturday in the centre of the Swedish capital, holding speeches and parading along the waterfront.
Thousands of Stockholmers gathered to protest against the neo-Nazis. The rally took place behind a massive police cordon, set up to prevent direct contact between the neo-Nazis and the anti-Nazi protesters.
While the protesters were unable to break through the police barrier, they hurled bottles, bricks and fireworks across the security fence.
One demontrator was taken to the hospital by ambulance, although police did not clarify for press how he had been injured.
Fifteen people were apprehended , reportedly for violating anti-mask laws. In Sweden it is illegal to wear a mask preventing identification at demonstration which disturbs public peace.
The anti-Nazi protest was also so loud that at times it almost drowned out the Neo-Nazi speakers.
At another anti-Nazi demonstration in the southern Swedish city of Malmö last weekend, a number of protesters were injured when mounted police charged into the crowd.
The Party of the Swedes is recruiting its members mainly with an appeal to restrict immigration, but it attracts only a tiny proportion of Swedes.
The party garnered 681 votes out of the 5.8 million cast in the most recent parliamentary elections in 2010.