Boris Tadic, the Serbian President, has received death threats from nationalists for "betraying the Serb people" by seeking closer ties with the European Union, officials said.
President Tadic backed the signing of a stabilisation and association agreement with the EU last week over the objections of hardliners, who said it amounted to a recognition of independence for Kosovo, since the EU supported secession for the former Serbian province.
"We are aware of the death threats President Tadic received," the state prosecutor's office said yesterday. "Relevant state institutions are taking all measures necessary to protect the President and identify the perpetrators."
The President's office declined to comment on the death threats. The Serbian daily Blic quoted one letter as saying that Mr Tadic would get a bullet to the head for betraying the country.
The secession of Kosovo, Serbia's medieval heartland, polarised Serbia between hardliners, who want to freeze ties with the EU, and pro-Western liberals, who think there is a way to move towards membership and still not give up Kosovo.
The government, a coalition of Mr Tadic's Democrats with the outgoing nationalist Prime Minister, Vojislav Kostunica, collapsed under the strain. Campaigning for elections to be held on Sunday has focused largely on the EU-Kosovo dilemma.
Mr Tadic urged politicians yesterday to calm down and not create "bad blood in the country" for the sake of a few more percentage points in the election.
There were several mafia-style murders during Slobodan Milosevic's autocratic rule in the 1990s. The most recent was the assassination in 2003 of the prime minister, Zoran Djindjic, by a sniper connected to nationalist criminal groups.