Some 35,000 Serbs living in the Mitrovica region were voting in a referendum, with polling stations open in the main city Kosovska Mitrovica, in Zvečani, Zubin Potok and surrounding villages, according to news agency BETA, EurActiv's partner publication in Serbia.
The question to be answered by voters is: "Do you recognise the institutions of the so-called Republic of Kosovo?"
A commanding no vote is expected.
The mayor of the Serb part of the divided city of Kosovska Mitrovica was quoted by Euronews as saying that the vote would send a message to Kosovo's Albanians, and to Belgrade politicians whom he said were making conciliatory moves towards the authorities in Priština.
The vote takes place ahead of the 4th anniversary of the independence of Kosovo (see background) and just before a landmark decision to grant Serbia the status of EU candidate country. The December 2011 EU summit agreed that such a decision could be taken in February and confirmed at the 1-2 March EU summit.
Asked by EurActiv to comment on the referendum in Mitrovica, Maja Kocijancic, spokeswoman for EU foreign policy chief Catherine Ashton, said that the EU was concerned about the need of a solution for this territory.
"Violence and barricades solve nothing. Nor do referenda. We will get to a solution only through calm, consultation and dialogue," she said.
Kocijancic added that the EU executive took into account recent statements by government officials in Belgrade, including by Serbian President Boris Tadić, who called the referendum unconstitutional.
Candidate status at stake
BETA agency quoted the German ambassador to Serbia, Wolfram Maas, saying that he hoped Serbia would meet the conditions required to obtain candidate status at the March summit, but that he was not overly optimistic.
"I'm not an optimist but neither am I a pessimist. The conditions for candidacy are clear and they are simple to meet - the application of the agreements with Priština, EULEX and KFOR carrying out their mandate across the entire territory of Kosovo and the agreement on the regional representation of Kosovo," said Maas in comments made Monday (13 February).
EULEX is the EU-led law enforcement mission in Kosovo and K-FOR is the NATO peacekeeping mission.
Maas stressed that Serbia's place was in the EU and strongly criticised the stance of the Democratic Party of Serbia, led by Tadić, that Belgrade was losing out by implementing the Stabilisation and Association Agreement.
"Whoever claims this either does not know what it is about or is, simply, lying. During the three years the agreement has been implemented, €500 million has been lost but €1.5 billion has been received," said Maas.
Serbia is to hold parliamentary elections at the end of April or the beginning of May, with populism on the rise and increased attacks against the president's Democratic Party, seen by many as the key pro-democratic force in Serbia. The press in the region also reported rumours of Tadić being "seriously ill".