Key local elections in Kosovo on Sunday, closely watched by Brussels, will be a crucial test for both Pristina and Belgrade after an EU-brokered landmark deal to improve their relations.
The turnout of Kosovo minority Serbs, especially in the north where they make majority and have so far rejected Pristina's authority, will be vital for the success of the polls.
Serbia still rejects Kosovo's 2008 independence, but it has encouraged the ethnic Serb community there to vote as part of the April deal with Pristina to normalise relations.
Kosovo, the territory which sparked a war between Serb forces and ethnic Albanian rebels in 1998-1999, remains the main stumbling block to Serbia's bid to join the European Union.
The deal with Pristina had helped Serbia secure the green light to begin membership talks with Brussels, and holding up its end of the accord is vital for Belgrade.
For Kosovo, a free and fair vote with a significant Serb turnout would be a positive mark in its own push for negotiations on an EU membership bid. Kosovo's independence is recognised by most EU states.
EU foreign policy chief Catherine Ashton called the elections "a key moment in Kosovo's future and an important element in the process of normalisation of relations between Kosovo and Serbia."
"The EU will be following closely the conduct of the elections," she said in a statement.
Some 120,000 Serbs live in Kosovo, but the 40,000 living in the north, which has maintained a certain control of institutions, are torn over whether to vote in the elections.
Hardline nationalist Serbs have actively campaigned against the vote, calling for a boycott.
Overnight Friday, two masked men attacked a Serb candidate for mayor in Kosovska Mitrovica, the key town in the north.
Lamberto Zannier, secretary general of the Organisation for Security and Cooperation in Europe, raised concerns about the nationalists' campaign and warned of "intimidation of candidates and voters."
Belgrade has strongly backed the polls, with Serbian President Tomislav Nikolic, Prime Minister Ivica Dacic and powerful deputy Prime Minister Aleksandar Vucic issuing a joint appeal to the voters to cast their ballots.
"Only a high turnout will secure the Serbs' survival in Kosovo... Every other result is a defeat," they said in a joint statement.
Vucic visited Kosovo Friday to make a final appeal to ethnic Serbs to go to the polls.
"Vote for your own good," he told a rally in the Serb-populated enclave of Gracanica, near the capital Pristina.
However the hardliners' campaign seemed to having an effect, with 43.5 percent of northern Kosovo Serbs saying they would not vote, according to an October survey conducted by the United Nations Development Programme (UNDP).
Only 15.8 percent of some 400 people polled said they intend to vote, while 23 percent were still undecided.
"By taking part in the elections organised by Pristina, Serbs from the north will recognise the existence of" Kosovo as an independent territory from Serbia, Belgrade-based political analyst Dusan Janjic told AFP.
For Kosovo's Prime Minister Hashim Thaci, the elections will be a test of his support for improving relations with Belgrade.
Thachi, who has come under fire from the opposition for his talks with Belgrade, is nevertheless expected to win most of the ethnic Albanians' votes on Sunday with his Democratic Party of Kosovo.
Some 1.7 million people across the territory are eligible to vote in the elections for deputies and mayors of 36 Kosovo municipalities.
Polling stations will open at 0600 GMT and close 12 hours later. Preliminary results are expected during next week.