Kosovo police have used tear gas to disperse demonstrators gathered to protest the arrest of an opposition lawmaker.
Scores of opposition supporters massed in front of the government headquarters in Pristina on November 18.
Police fired tear gas after some protesters threw stones and paint at the building.
The fresh unrest came hours after Donika Kadaj-Bujupi was arrested. Arrest warrants were also issued for three of her opposition colleagues.
They are accused of taking part in protests inside parliament over the past two months with tear gas and pepper spray, whistles, and water bottles.
The opposition wants the government to withdraw from a deal with Serbia giving more powers to ethnic Serbian communities and from one with Montenegro on border demarcation.
Protesters remained in front of the government building until late evening and clashed with police, who used armored vehicles to disperse them.
Police said at least seven policemen and two citizens were injured and a large number of vehicles were burnt or damaged.
By late evening 22 "violent" protesters had been arrested, police said, adding that many public buildings and other properties were damaged.
Kosovo in 2008 declared independence from Serbia, which is not recognized by Belgrade.