The Serbian parliament has voted to replace assassinated PM Zoran Djindjic with his reformist ally Zoran Zivkovic.
Mr Zivkovic promises to continue Mr Djindjic's reforms
Mr Zivkovic told the Serbian parliament, holding its first sitting since Mr Djindjic's death, that his government would press on with reforms and thwart any attempts at destabilising the country.
More than 750 people have been arrested as the authorities move against the Serbian underworld figures being blamed for the murder, Mr Zivkovic said.
Mr Djindjic, shot dead in central Belgrade last week, had predicted his own death during a meeting in February, said UN war crimes chief prosecutor Carla del Ponte in an interview published on Tuesday.
He knew what the connections were between the old paramilitary apparatus and the mafia
Carla Del Ponte
War crimes tribunal chief prosecutor
"He gave me a full run-down of his reform programmes. And then he suddenly told me: 'They'll kill me'," Ms Del Ponte told the Italian newspaper La Repubblica.
"He was explaining to me that after beginning the reform of the economy, he intended to tackle the police and the army. It was a very
delicate reform and very dangerous and the prime minister knew that perfectly well," she said.
He also knew, she said, that the fight against organised crime went hand in hand with the arrest of war criminals.
In parliament, Mr Zivkovic said the assassination of Mr Djindjic had a clear political
background and was not linked solely to the mafia.
Djindjic predicted his own death, says Del Ponte
A great man had been lost, he said.
Serbia's new administration would be "a cabinet of Zoran Djindjic's continuity", with the same
tasks, goals and people, Mr Zivkovic said.
Mr Zivkovic, a member of Mr Djindjic's Democratic Party, is a close ally of the former leader.
His immediate task will be to try to maintain political stability.
That means trying to keep together a 16-party coalition which is currently governing the republic.
Serbia remains under a state of emergency following the assassination.
Those arrested include Serbia's most famous folk pop singer, Ceca, the widow of former warlord Arkan.
It is claimed she has had close contacts with the chief suspects in the police investigation, including Milorad Lukovic, also known as Legija.
Mr Lukovic is a former member of Arkan's paramilitary unit, who is now said to be the leader of one of Serbia's biggest organised crime gangs.
Police in Serbia said on Tuesday they had captured two key suspects, Dragan Ninkovic and Zoran Vukojevic, alleged to be members of a leading criminal gang in Belgrade.