Protesters besieged the central police station in the Kosovar capital, Pristina, on October 12 hours after a prominent opposition politician was detained, lobbing concrete and stones at police, who returned fire with tear gas.
Several hundred protesters converged on the central police station at the urging of the opposition Self-Determination party, which said its founder, Albin Kurti, had been arrested.
Kurti last week released tear gas in Kosovo's parliament, part of a long-running protest against a landmark deal brokered by the European Union to normalize relations between Kosovo and Serbia.
"Police have arrested Albin Kurti," Self-Determination said on its Facebook page. "They are sending him to the main police station in Pristina. We invite all activists, supporters, and citizens to gather in front of the police station."
Police said Kurti had been taken in for questioning.
Kurti was later released. He told a crowd of his supporters that he would see them at the next rally.
"We will not give up. Let's stay united," he said.
Several hundred demonstrators converged on the station in the center of the capital, throwing stones and concrete ripped up from a square being repaved. The projectiles smashed windows as police fought back with tear gas.
Opposition legislators have been protesting against an accord reached in August between Kosovo's government and Serbia in which Kosovo agreed to give more financial and legislative rights to its minority Serb community, setting up an association of Serb-run municipalities.
But the opposition believes the move will deepen the ethnic divide and increase Serbia's power in Kosovo. Kurti says it represents a threat to Kosovo's hard-won sovereignty.
Kosovo, whose population is predominantly ethnic Albanian, declared independence from Serbia in 2008. But Belgrade has never recognized the move and still considers the breakaway territory as its southern province.
Along with releasing tear gas in parliament, opponents of the deal have blown whistles and thrown eggs to disrupt recent legislative sessions in protest of the plan.