Opposition lawmakers released tear gas in Kosovo's parliament and protesters outside threw petrol bombs in an unsuccessful attempt to stop Hashim Thaci, who they say gave too much power to ethnic Serbs, from being elected president.
Twenty-one officers were injured in the streets of Pristina during Friday's session when police used tear gas and water cannons to disperse protesters.
Thaci, 47, helped to clinch an EU-brokered agreement in 2015 that gives a small Serb minority more power over local government decisions and raises the possibility of financing from Belgrade. With 71 votes in a 120-seat parliament, he will be Kosovo's fourth president and serve five years in the largely ceremonial role.
Four hours into Friday's session, led by Thaci's Democratic Party of Kosovo, opposition lawmakers threw three tear gas canisters in the chamber, prompting the speaker, Kadri Veseli, to eject 11 MPs.
Security forces wear gas masks at the Kosovo assembly, after opposition lawmakers released tear gas canisters disrupting a parliamentary session in Kosovo's capital Pristina, Feb. 26, 2016.
An hour later, tear gas was thrown again, but the choice of Thaci was approved despite a delay.
"I will always work to serve the country, all its citizens and respect the constitution," Thaci told the parliament after the vote.
Born and raised in the hard-line region of Drenica, Thaci led the guerrilla insurgency against Serbian forces in 1998-99. He served as Kosovo's prime minister when it declared independence in 2008.
But in a 2011 Council of Europe report he was identified as a leader of a group that had committed war crimes against Serbs and had harvested organs from Serbs captured in the 1998-99 Kosovo war. Thaci has denied the accusations.
Serbs driven out
Kosovo declared independence from Serbia in 2008, almost a decade after NATO airstrikes drove out Serbian security forces accused of killing and expelling ethnic Albanian civilians during a counterinsurgency war.
Many Kosovo Albanians believe last year's accord with Serbia could erode that hard-won sovereignty, though its status is unclear after a Kosovo constitutional court ruling in December that parts of it breach the country's laws.
Opposition parties have been protesting for four months against the deal with Serbia and have staged street protests, repeatedly thrown tear gas in parliament, clashed with police and last month set a government building on fire.
"Our protests will not stop. They will get bigger," Visar Ymeri, leader of the biggest opposition party, Vetevendosje, said at a news conference.