The Nato-led peacekeeping force in Kosovo, KFOR, on Tuesday raised the number of its troops injured in fierce clashes with ethnic Serbs to 30.

The Serbs had tried to take over the offices of one of the municipalities in northern Kosovo where ethnic Albanian mayors took up their posts last week.

A statement said that 11 Italian soldiers and 19 Hungarian ones “sustained multiple injuries, including fractures and burns from improvised explosive incendiary devices”. It added that three Hungarian soldiers were “wounded by the use of firearms”, but their injuries are not life-threatening.

The Serbs clashed with Nato troops in the municipality of Zvecan, 45km north of the capital, Pristina.

“Both parties need to take full responsibility for what happened and prevent any further escalation, rather than hide behind false narratives,” said KFOR commander Major-General Angelo Michele Ristuccia.

Ethnic Serbs plan to gather again on Tuesday.

Serbian President Aleksandar Vucic spent the night with his troops on the border with Kosovo. They were placed on the highest state of alert on his orders last week. Vucic said 52 Serbs were injured in the clashes, three seriously.

Kosovo police said four people were detained.

The violence was the latest incident as tensions soared over the past weekend when ethnic Serbs in northern Kosovo tried to block recently elected ethnic Albanian officials from entering municipal buildings. Kosovo police fired tear gas to disperse the crowd and let the new officials into the offices. Serbia put the country’s military on high alert and sent more troops to the border with Kosovo.

Kosovo and Serbia have been foes for decades, with Belgrade refusing to recognise Kosovo’s 2008 sovereignty.

The US and the EU have stepped up efforts to help solve the Kosovo-Serbia dispute, fearing further instability in Europe as Russia’s war rages in Ukraine. The EU has made it clear to both Serbia and Kosovo that they must normalise relations.