The annual "Mirdita, Dobar Dan," which promotes cultural exchanges between the two countries opened Wednesday at a time of rising tensions. It is organized by non-government groups advocating cooperation in the Balkan region.
Carrying Serbian flags, several dozen nationalists tried to push through a police cordon securing the area of the event. Serbian nationalists oppose any normalization of relations between Serbia and its former province that declared independence in 2008. Tensions soared on Tuesday over a Kosovo police raid in Serb-populated northern Kosovo.
Kosovo's prime minister is resisting the European Union's call to revoke or suspend a 100% tariff on Serb goods.
Ramush Haradinaj said the tariffs would continue so long as Serbia does not recognize Kosovo's borders.
Pristina set the 100% tariff last November saying it will only be lifted when Belgrade recognizes Kosovo's sovereignty and stops preventing it from joining international organizations.
EU's foreign policy chief Federica Mogherini urged Kosovo to revoke or suspend the tariff so negotiations on normalizing relations can resume.
The imposition of the tariff has stalled Kosovo's EU-sponsored talks with Serbia.
Serbia doesn't recognize Kosovo's 2008 declaration of independence. Relations have become increasingly strained this week after Kosovo police launched a raid inside Kosovo's Serb-populated area.
A Kosovo prosecutor says he wants the immunity of a Russian staff member of the United Nations to be lifted so he can be prosecuted for obstructing police during an operation in Kosovo's Serb-populated area.
Gazetaexpress local private media said prosecutor Shyqri Syla confirmed the immunity request.
The Russian, who has not been formally named by Kosovo authorities, was arrested along with a local U.N. staffer at a roadblock built by ethnic Serbs, who were trying to prevent police entering the area. While the Russian was later released, it's not clear whether the local U.N. staff member is still being detained.
Five police officers and six civilians were injured during Tuesday's raid which authorities say was designed to apprehend members from an organized criminal gang. The raid has soured already tense relations between Kosovo and Serbia.
The Kosovo prosecutor's office says six ethnic Serbs who hampered Kosovo's police operation a day earlier in Serb-dominated northern Kosovo have been arrested and charged with obstruction of justice.
A statement Wednesday said the six raised road barricades with vehicles and other objects at a village in the northern Zubin Potok commune, trying to make it impossible for Kosovo police to detain crime suspects in the area.
Kosovo police said ethnic Serbs in northern Zubin Potok commune made "an armed resistance."
A U.N. vehicle with two staff members, a local citizen and a Russian, was also found there. Both were detained and later released.
The Kosovo police operation against organized crime and corruption, which heightened tensions with Serbia, ended with arrest of 19 local police officers.
Five officers and six citizens were injured during the operation.
The European Union's top diplomat is urging Kosovo and Serbia to return to the negotiating table and normalize relations amid high tensions following an armed raid by Kosovo police in the Serb-dominated north of Kosovo.
EU foreign policy chief Federica Mogherini said Wednesday that the incident "shows us that the status quo is not sustainable and that both Pristina and Belgrade need to come back to the dialogue table."
Mogherini added: "I see the risk of the dark forces of the past coming back, in terms of confrontation, even of conflict" if the two sides continue facing off.
Serbia put its troops on full alert Tuesday after armed Kosovo police fired tear gas and arrested about two dozen people in what they called an anti-organized crime operation in majority Serb areas in Kosovo.
Russia and Serbia have blamed pro-NATO and Western influences for an armed raid by Kosovo police in the Serb-dominated north of Kosovo that raised tensions in the region.
Russian Foreign Minister Sergey Lavrov said Wednesday that Tuesday's incident was instigated by "those who want to create a buffer zone from Russia on the Balkans" and who "want to push everyone to NATO."
The armed operation angered Serbia, which immediately put the Serbian army on full alert in response. A Russian U.N. employee was among more than two dozen people arrested.
Serbian President Aleksandar Vucic says NATO-led peacekeepers in Kosovo "lied" when they said they had informed Belgrade in advance of the police action.
The raid was the latest flare-up in long-simmering tensions between Serbia and its former province.