About 25 Nato peacekeeping soldiers defending three town halls in northern Kosovo have been injured in clashes with Serb protesters, while Serbia’s president put the army on the highest level of combat alert. Kfor, the Nato-led peacekeeping mission to Kosovo, condemned the violence. “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,” it said in a statement. Serbia’s state broadcaster, RTS, quoted its defence ministry as saying two Serbs were injured in clashes. Kosovo’s president, Vjosa Osmani, accused her Serbian counterpart, Aleksandar Vučić, of destabilising Kosovo. “Serb illegal structures turned into criminal gangs have attacked Kosovo police, Kfor officers & journalists. Those who carry out Vučić’s orders to destabilise the north of Kosovo must face justice,” Osmani tweeted. The tense situation developed after ethnic Albanian mayors took office in northern Kosovo’s Serb-majority area after elections that the Serbs boycotted – a move that led the US and its allies to rebuke Pristina on Friday. In Zvecan, one of the towns, Kosovo police – staffed by ethnic Albanians after Serbs quit the force last year – sprayed pepper gas to repel a crowd of Serbs who broke through a security barricade and tried to force their way into the municipality building, witnesses said. Serb protesters in Zvecan threw teargas and stun grenades at Nato soldiers. Serbs also clashed with police in Zvecan and spray-painted Nato vehicles with the letter “Z”, referring to a Russian sign used in the war in Ukraine. In Leposavic, close to the border with Serbia, US peacekeeping troops in riot gear placed barbed wire around the town hall to protect it from hundreds of angry Serbs. Later in the day, protesters threw eggs at a parked car belonging to the new Leposavic mayor. Vučić, who is the commander in chief of the Serbian armed forces, has raised the army’s combat readiness to the highest level, the defence minister, Miloš Vučević, told reporters. “This implies that immediately before 2pm [noon GMT], the Serbian armed forces’ chief of the general staff issued additional instructions for the deployment of the army’s units in specific, designated positions,” Vučević said, without elaborating. Nato peacekeepers also blocked off the town hall in Zubin Potok to protect it from angry local Serbs, witnesses said. Igor Simić, the deputy head of the Serb List, the biggest Belgrade-backed Kosovo Serb party, accused Kosovo’s prime minister, Albin Kurti, of fuelling tensions in the north. “We are interested in peace. Albanians who live here are interested in peace, and only he [Kurti] wants to make chaos,” Simić told reporters in Zvecan. Serbs, who comprise a majority in Kosovo’s north, have never accepted its 2008 declaration of independence from Serbia and still see Belgrade as their capital more than two decades after the Kosovo Albanian uprising against repressive Serbian rule. Ethnic Albanians make up more than 90% of the population in Kosovo as a whole, but northern Serbs have long demanded the implementation of an EU-brokered 2013 deal for the creation of an association of autonomous municipalities in their area. Serbs refused to take part in local elections in April and ethnic Albanian candidates won the mayoralties in four Serb-majority municipalities – including North Mitrovica, where no incidents were reported on Monday – with a 3.5% turnout. Serbs demand that the Kosovo government remove ethnic Albanian mayors from town halls and allow local administrations financed by Belgrade to resume their work. On Friday, three out of the four ethnic Albanian mayors were escorted in to their offices by police, who were pelted with rocks and responded with teargas and water cannon to disperse the protesters.