NATO-led peacekeeping force KFOR clashed with protesters on Monday in northern Kosovo, where the Serb minority is protesting ethnic Albanian mayors taking office in Serb-majority areas. The Serb communities had boycotted the election that led to new mayors being installed.

KFOR (short for Kosovo Force) reportedly used tear gas and stun grenades against protesters in Zvecan, a Serb-dominated town some 45 kilometers (28 miles) from Pristina.

KFOR said in a statement that "around 25" members of the "multinational contingent" were wounded during the altercation.

"While countering the most active fringes of the crowd, several soldiers of the Italian and Hungarian KFOR contingent were the subject of unprovoked attacks and sustained trauma wounds with fractures and burns due to the explosion of incendiary devices," KFOR wrote. 

Some reports put the number of wounded KFOR peacekeepers higher than 25. Separately, Serbian-language news outlet Kossev cited a health official as saying over 50 people have required medical assistance in a Serb-controlled hospital, and that one person was shot and remained in critical condition.

Italian PM says further attacks on peacekeepers won't be tolerated

Italy's Foreign Minister Antonio Tajani said on Twitter that 11 Italians were among the KFOR forces wounded, and that three of them were in a serious but not life-threatening condition. 

Italian Prime Minister Giorgia Meloni later said that further attacks on international peacekeepers would not be tolerated, but she also seemed to rebuke Kosovo for its role in creating the scenes.

"It is essential to avoid further unilateral actions by the Kosovar authorities and that all parties involved immediately take a step back to lower tensions," Meloni said. 

KFOR deployed after earlier clash between Kosovo police and protesters

The NATO-led force had been deployed to stem brewing tensions between the protesters and the Kosovo police.

Kosovo police said their officers had sprayed pepper gas earlier on Monday to repel a crowd of protesters. 

"The protesters, using violence and throwing tear gas, tried to cross the security cordons and make a forced entry into the municipality facility," Kosovo police said in a statement. "Police were forced to use legal means, such as [pepper] spray, to stop the protesters and bring the situation under control."

Serbian, Kosovar leaders exchange blame

Ethnic Serbs last year withdrew from Kosovo's state police in protest, meaning officers are now exclusively ethnically Albanian. 

Serbia, Kosovo's northern neighbor which still sees Kosovo as a breakaway Serbian province, responded to the unrest by putting its military on alert and moving additional troops to the border.

On Monday, Serbian President Aleksandar Vucic said that 52 Serbs were
injured in the clashes, three of them seriously. Kosovo President Vjosa Osmani meanwhile accused Vucic of destabilizing the country.

"Serb illegal structures turned into criminal gangs have attacked Kosovo police, KFOR [peacekeeping] officers & journalists. Those who carry out Vucic's orders to destabilise the north of Kosovo, must face justice," Osmani said on Twitter.

Kosovo is mostly populated by ethnic Albanians and has declared independence from Serbia in 2008. In recent years, the two sides have been engaged in EU-mediated talks aimed at normalization.

How did we get here? 

The latest unrest can be traced back to local elections in April. The Serbs decided to boycott the vote in protest to the central government's policies. This led to ethnic Albanian candidates winning the mayoral positions in Serb-dominated towns — despite overall turnout of just 3.5% in the region.

Then, the Kosovo government deployed heavily armed police forces in Serb-populated regions to move the new mayors into town halls. On Friday, while three of the four mayors were escorted into their offices by riot police — protesters pelted them with rocks and the police responded with tear gas and water cannons. The protesters then entered a standoff with Kosovo forces blocking access to official buildings.

Rare Western rebukes aimed at Kosovo

The Kosovo government faced unusually strong criticism from its key ally, the US, and other Western partners as the unrest flared over the weekend.

"We strongly condemn the actions by the Government of Kosovo that are escalating tensions in the north and increasing instability," said US State Secretary Antony Blinken, calling on Prime Minister Albin Kurti to "immediately halt these violent measures and refocus on the EU-facilitated dialogue." 

On Sunday, NATO Secretary General Jens Stoltenberg also urged Pristina and Belgrade to engage in dialogue.

"Pristina must de-escalate and not take unilateral, destabilizing steps. [NATO's KFOR] will continue to ensure a safe and secure environment," Stoltenberg said.

The informal Kosovo "Quint" decision-making group — comprised of the US, France, Italy, the UK and Germany — also issued a joint statement calling for restraint from all sides and a de-escalation of the situation on Friday. Its embassies followed up on this again late on Sunday. 

"We reiterate our May 26 statement condemning Kosovo's decision to force access into municipal buildings in the north of Kosovo despite our repeated calls for restraint," the ambassadors said, adding: "the Quint and the EU's expectation is that the authorities of the Government of Kosovo will undertake no new measures to force access to the municipal buildings."

msh/dj (AFP, AP, Reuters)

A previous version of this article described KFOR troops as "NATO soldiers." While KFOR is led by NATO, it also includes troops from non-NATO members. This has now been corrected. DW apologizes for the error.