In Zvecan, police said ten people were arrested on Friday after they blocked access to the Town Hall led by an Albanian mayor. There were also disturbances in Zubin Potok, Leposavic, and northern Kosovska Mitrovica.
Earlier in the day, Serbs also switched on their alarm sirens in the four communes, including the main Northern Mitrovica town, in a warning sign and call to assemble.
Albanians make up the majority of the population in Kosovo but are a minority in the north, which is nearer to Serbia and thus has a majority of ethnic Serbs.
Recent municipal elections were boycotted by the Serbian community leading to the Albanian mayors being elected. Now, ethnic Serbs are refusing to recognise the authority of these mayors.
The reason the Serbs had objected to the election was in protest over the establishment of an association between the two communities to coordinate work on education, health care, land planning and economic development at a local level.
Serb representatives left their administrative posts last year in protest at the association.
The two sides have tentatively agreed to back an EU plan on how to proceed, but tensions continue to simmer.