The neo-Nazis, members of the Swedish Resistance Movement (SMR), were stopped by police on their way to Myntorget in the Gamla Stan area of Stockholm on Saturday afternoon.
"They were stopped near Riksbron. They were behaving badly and were armed with golf-clubs and stones," said police spokesperson Ann-Charlotte Wejnäs to TT.
A demonstration arranged by the Serbian youth organization in Sweden was being held at the time on the nearby square. 400 Serbs had gathered to demonstrate against Kosovo's declaration of independence.
Police arrested two of the neo-Nazis, one for violent resistance and the other for intent to commit assault. The remainder were dispersed.
A further group of 20 people was broken up by police in the city centre after having having thrown Bengal flame fireworks at cars on Kunsgsgatan.
"They were driven to various locations on the outskirts of the city," said Wejnäs.
Demonstrations protesting the declaration of independence in Kosovo were held in Stockholm, Gothenburg and Malmö on Saturday. Nato and the USA were the target of much of the anger expressed by the Serb demonstrators and speakers.
Demonstrators signed petitions challenging the the Swedish government to refrain from recognizing Kosovo's independence. The petitions will be sent to the foreign minister, Carl Bildt.