At least 34 soldiers of NATO’s peacekeeping mission in Kosovo were injured during clashes with protesters in the northern part of the country Monday, according to the Italian defense ministry, writes CNN.

Tensions have risen in the past week after ethnically Albanian mayors took office in northern Kosovo, a majority Kosovo Serb area, following April elections that Kosovo Serbs had boycotted.

NATO’s Kosovo Force (KFOR) said the recent developments prompted them to increase their presence in northern Kosovo, which they later said turned violent.

The Italian defense ministry said 14 of its KFOR peacekeeping soldiers were injured when protesters threw “Molotov cocktails, with nails, firecrackers and stones inside”. Hungarian and Moldovan soldiers were also among the injured peacekeeping troops, according to the Italian defense ministry.

Meanwhile, Nemanja Starović, Serbian State Secretary in the Ministry of Defence, offered a different version of events than what was outlined by NATO countries. He said “many” protesters were injured in the clashes and accused KFOR of using flash grenades when the “peaceful” protesters had “decided to disperse and continue the protest tomorrow morning”.

Kosovo, which is mainly ethnically Albanian, won independence from Serbia in 2008. But Serbia still considers Kosovo to be an integral part of its territory as do the Serbs living in northern Kosovo. NATO has troops stationed in Kosovo to maintain peace, with tensions often flaring between Serbia and Kosovo.