Serbian Interior Minister Dusan Mihajlovic said a gunman had opened fire on a car in his motorcade in a pre-dawn attack in central Belgrade, earlier today.
He declined to comment on media speculation that the incident, which took place shortly after midnight, was an assassination bid.
But several political parties belonging to the ruling DOS democratic alliance condemned it as a murder attempt.
Police officer Dragan Pantic, in charge of the investigation, told a news conference no one had been injured in the shooting, which happened after Mr Mihajlovic's car and another containing his bodyguards stopped at a traffic light.
A man whom he named as casino owner Milojica Djurisic, got out of his car with a gun and approached another car nearby which had no connection with Mr Mihajlovic's convoy.
Mr Mihajlovic's car rushed away and the escorting car was about to follow when Djurisic opened fire.
Without realising that it was a police car, Mr Djurisic shoots and our colleagues return fire, Mr Pantic said. All those involved had been identified, he said.
Meanwhile, a retired Croatian general is refusing to turn himself in to war crimes investigators without guarantees that he will not face trial at the UN court in The Hague, officials said.
Mirko Norac, 34, is suspected of being responsible for killing some 40 ethnic Serb civilians in the central town of Gospic at the outbreak of the 1991-95 conflict between Zagreb and secessionist Serbs.
President Stipe Mesic yesterday asked Mr Norac to meet with him to discuss his transfer to authorities but the retired general failed to turn up.