Frictions rose at Kosovo's border with Serbia on September 20 as Kosovar authorities deployed special police units to enforce a policy of removing Serbian license plates from vehicles entering Kosovo.
The tensions are part of a spat between the two former Yugoslav neighbors over reciprocal recognition of license plates in the context of a wider dispute over sovereignty.
Serbian authorities for years have insisted on the removal of Kosovar license plates that cross their mutual border.
Kosovar authorities had said that from September 20, they would be replacing Serbian-issued license plates on vehicles entering from that country with temporary plates.
Pristina described it as a "reciprocity" action, echoing the language of Kosovar Prime Minister Albin Kurti since he emerged as a leading national politician in late 2019 and returning as prime minister in March.
Officers of a Kosovar special police unit were deployed along with armored vehicles to two of the border crossings, Jarinje and Brnjak, on September 20 to implement the license-plate requirement on Pristina's behalf.
They were reportedly responding to a protest by hundreds of Kosovar Serbs who drove to the border in their cars to block a border checkpoint.
Serbia refuses to recognize the 2008 declaration of sovereignty by its former province, whose independence is recognized by around 110 countries but whose presence in some international organizations is still prevented by the impasse.
The European Union is mediating years-long negotiations aimed at normalizing relations between Serbia and Kosovo, within which both sides have pledged to allow the mutual flow of traffic at their border.
Kosovo now says the deal has expired.
The leader of an ethnic Serb party backed by Belgrade traveled to the Jarinje crossing to demand a solution to the license-plate problem and insist on the Serb community's right to protest.
Kosovar authorities asked Serbian List leader Goran Rakic and others to disperse.
"We hear information that this is not directed against the Serbian people," Rakic said, countering, "This is directed against the Serbian people."
In Belgrade, Serbian President Aleksandar Vucic responded to the tensions at the Kosovar border by scheduling a crisis meeting of Serbia's national security council.