Three Serbs and one KFOR soldier were injured in clashes in northern Kosovo on Friday.

According to Serbia’s RTS TV channel, the three Serbs were injured when KFOR troops fired rubber bullets. One Serb has been hospitalized in serious condition. Local authorities said there was reason to believe KFOR troops had fired live bullets.

Hundreds of Serbs clashed with KFOR troops in armoured vehicles near a barricade outside the town of Zvecan in a Serb-dominated northern area of Kosovo, pelting them with stones.

Kosovo’s ethnic Serb enclave in the north of Kosovo barricaded the main roads after the authorities in Pristina installed customs officers at the Jarinje and Brnjak border crossings with Serbia. Serbia does not recognize Kosovo as a sovereign country.