Angered by Slobodan Milosevic's extradition, Yugoslavia's prime minister and his Montenegrin allies in the federal government announced their resignations Friday in a move expected to hasten the collapse of the government.

The resignations of Zoran Zizic and other former Milosevic allies could even lead to a split between Yugoslavia's two remaining republics, Serbia and the much smaller Montenegro, completing the disintegration of the country that began shortly after Milosevic took power.

Thousands of Milosevic's supporters, enraged by his sudden extradition to a U.N. war crimes tribunal in The Hague, rallied Thursday outside the prison where he was jailed until his extradition chanting "treason." The mob moved to Belgrade's main square, where it swelled to 3,000 people. Several television cameramen were beaten.

The officials said their resignations meant the collapse of the Cabinet, which is made up of Serbia's pro-democracy officials and ministers from Montenegro who turned their backs on Milosevic after his ouster last October.

The Montenegrin officials, who met in the republic's capital Podgorica, said in a statement that Milosevic's extradition to the tribunal in The Netherlands was "illegal and unconstitutional" and "jeopardizes the functioning of Yugoslavia and its existence"

Zizic said he would hand in his formal resignation at a Cabinet meeting in Belgrade later Friday. The leader of the Montenegrin faction, Predrag Bulatovic, said the move means an end of the Serb-Montenegrin coalition on the federal level.

Milosevic was handed over to tribunal in The Hague on Thursday by the Serbian government, which ignored a federal Constitutional Court ruling that banned his extradition.

Late Thursday, Yugoslav President Vojislav Kostunica described the Serbian government's unilateral move as "illegal and unconstitutional," saying the extradition was carried out without respect for legal procedure.

The state news agency Tanjug said Kostunica was informed of the handover only after it happened.

Serbian Prime Minister Zoran Djindjic, who oversaw the extradition effort, said Yugoslavia had no choice but to surrender Milosevic or face renewed international isolation and the loss of much-needed foreign aid.

The rift between Kostunica and Djindjic, who together managed to remove Milosevic from power last October, could lead to the breakup of Serbia's pro-democracy alliance.

Meanwhile, Serbia's president, who was indicted by the tribune along with Milosevic, soon may surrender to the court, an official said Friday.

Milan Milutinovic is "considering" giving himself up now that Milosevic is in The Hague to face trial on charges of crimes against humanity, an Interior Ministry official told The Associated Press, speaking on condition of anonymity.

"It might happen soon," the official said.

It was not immediately clear whether Milutinovic would offer to testify against Milosevic. Both men face charges in connection with alleged atrocities committed by Serb troops against ethnic Albanians during the 1998-99 war in Kosovo, a province of Serbia.

Milutinovic was close to Milosevic throughout the former president's 13-year rule. After Milosevic's ouster last October, Milutinovic sought to distance himself from the former leader's policies and offered to cooperate with Yugoslavia's new, pro-democracy authorities.

In a recent television interview, Milutinovic said the indictment against him was based on his official position as president of Serbia, Yugoslavia's main republic, but claimed he had little to do with the events in Kosovo.

"There is nothing that can be done, one cannot escape one's own destiny," Milutinovic told private BK television.

Three other top officials were also indicted for the Kosovo atrocities, including Nikola Sainovic, a former Yugoslav deputy prime minister; Vlajko Stojiljkovic, a former interior minister; and Gen. Dragoljub Ojdanic, former head of the Yugoslav army.