NATO has decided to deploy hundreds of reinforcements to strengthen Kosovo's international peacekeeping mission (KFOR) after Monday's violence in the town of Zvecan.

Hundreds of ethnic Serbs rallied outside Zvecan's town hall on Wednesday for a third consecutive day and held aloft a huge Serbian flag that stretched over 200 meters (660 feet) from the municipal building to the town centre.

KFOR soldiers encircled the town hall, additionally securing the building with a metal fence and barbed wire, an AFP journalist said.

Kosovo's ethnic Serb minority boycotted last month’s local elections held in northern Kosovo, where they are a majority. Last Friday, newly elected ethnic Albanian mayors moved into their offices with the help of Kosovo’s national police.

Serbs tried to prevent the new mayors from taking over the premises, but the police fired tear gas to disperse them.

The election boycott followed a collective resignation by Serb officials from the area, including administrative staff, judges and police officers, in November 2022.

The demonstrators decorated the fence -- erected by KFOR soldiers -- with Serbian flags.

Three vehicles of Kosovo special police -- whose presence sparks controversy in Serb-majority northern areas -- remained parked outside the town hall.

On Monday, Serbs engaged in fierce clashes with NATO peacekeepers, leaving more than 50 rioters and 30 international troops injured.

700 more troops

On Tuesday, NATO Secretary General Jens Stoltenberg condemned attacks on the alliance's forces in Kosovo, saying they were "unacceptable and must stop".

"We have decided to deploy 700 more troops from the operational reserve force for Western Balkans and to put an additional battalion of reserve forces on high alertness so that they can also be deployed if needed," Stoltenberg said.

"Violence sets back Kosovo and the entire region."

Serbia raised the combat readiness of its troops stationed near the border and warned it wouldn’t stand by if Serbs in Kosovo were attacked again.

The situation has again fueled fears of a renewal of the 1998-99 ethnic conflict in Kosovo between Serb forces and Albanian guerrillas, that claimed more than 10,000 lives and left more than 1 million homeless.

Kosovo declared independence from Belgrade after US-led NATO military intervention in 1999.

Kosovo’s independence has been recognized by about 100 countries, including the United States. Russia, China and five EU countries, most of them with separatist regions of their own, have sided with Serbia, preventing Pristina from having a seat at the United Nations.

Kosovo is mainly populated by ethnic Albanians, but the Serbs who make up around six percent of the population have remained largely loyal to Belgrade, especially in the north where they are a majority.