BELGRADE, Yugoslavia -- As day two of a new Yugoslavia dawns, the dominant question from Belgrade to Washington is: Where is Yugoslav President Slobodan Milosevic?
U.S. intelligence officials are watching all unusual flights in and out of Serbia for any signs that Milosevic may intend to seek refuge in another country, officials told CNN.
Late Thursday, after the world spent the day watching hundreds of thousands of Serbs rise up to seize control of the parliament building and the Serb television station, U.S. intelligence sources said Milosevic's suburban Belgrade home appears to have been vacated.
"The house is dark," said an informed official. "There is no security" around the home as would normally be expected, and there are no cars and no movement, the official said.
U.S. officials said they are closely watching the actions of a Ukrainian air transport plane that has been given permission to fly through Romanian airspace to Belgrade on Friday, where it is expected to pick up some passengers and immediately return to Ukraine.
"We are watching this one closely," said one official. "It may -- or may not -- be significant." Officials said that while they have information suggesting the flight is planned, the usual official flight plan has not been filed.
U.S. officials expressed some skepticism about reports that Milosevic is in a bunker in eastern Serbia, protected by army troops.
"You don't know what you don't know ... but this seems unlikely," said one U.S. official.
Huge open air party
The Yugoslav opposition was in charge of the capital's streets on Friday after a popular and almost bloodless revolution appeared to have swept Milosevic from power.
Belgrade turned into a huge open air party in the early hours of Friday, with dancing in the streets, as opposition supporters celebrated what they saw as their triumph.
On Thursday, demonstrators stormed the federal parliament as well as the building housing the executive of Milosevic's Socialist Party. Even his propaganda machine switched sides, many of his police joined the protesters, and the army stayed in its barracks.
After initial resistance from police, who fired tear gas, crowds burst into parliament, setting fire to some parts and ransacking filing cabinets. They also took over Serbian state television.
Kostunica wants sanctions lifted
The new political situation appeared to be confirmed shortly before midnight local time (2200 GMT) when Vojislav Kostunica appeared on state television described as the new president.
Kostunica is widely thought to have won the September 24 presidential election, although government-supplied results fail to show he received a majority, which is required to avoid a runoff. Observers say the government's nullification of the presidential vote on Wednesday may turn out to be the pivotal action that brought protesters into the streets.
In a wide-ranging interview, Kostunica revealed that he hoped sanctions imposed on Yugoslavia could be lifted as early as Monday. The sanctions were imposed in 1998 by the United States and some European nations in an attempt to compel Milosevic to stop cracking down on ethnic Albanians seeking the independence of Kosovo.
The opposition leader said he had been promised by France that the sanctions would be lifted at Monday's meeting of the European Council.
Kostunica also appealed to police to prevent looting.
Despite unanimous support for the opposition movement from western leaders, Kostunica said Yugoslavia would not forget "the NATO aggression." He also said, however, "we can't live against the grain" and that he hoped to be able to restore "normal relations with the world."
NATO waged a 78-day air campaign in 1999 after Serbian negotiators and Milosevic refused to agree to a pact that would have granted Kosovo substantial autonomy and placed NATO peacekeeping troops in the province. The bombing, along with the sanctions, severely damaged Yugoslavia's economy and infrastructure.
State television back on the air
Opposition leaders admitted they were "stunned" by the scale of the popular demonstration to oust Milosevic on Thursday.
State television initially reported that hooligans were attempting to take over the parliament. After that, its hourly news bulletins were dropped, and then it was knocked off air when protesters set the broadcast building ablaze.
The building was re-opened under a new name and began broadcasting for the first time pictures of the day's dramatic events in Belgrade to other parts of the country.
The footage shows police using tear gas to try to disperse the demonstrators. Some police, apparently siding with the opposition supporters, allowed some of the crowd into the building.
But CNN Belgrade Bureau Chief Alessio Vinci says one of the most surprising aspects of the demonstration was the lack of resistance offered by the security forces.
Very few police were seen at the height of the protest, and soldiers were seen shaking hands and smiling with the demonstrators.
The independent Beta news agency on Thursday night quoted an unnamed military source as saying, "The Yugoslav army will in no way interfere in street events. Yugoslav army members have always stayed aside, respecting their constitutional role."
Opposition leaders had said earlier that they wanted a statement from the army supporting Kostunica. No such statement has been forthcoming, and opposition leaders encouraged the demonstrators to spend all night on the streets until Milosevic officially admits defeat.
Vinci said the people are in a party mood and appear happy to remain outside.
"We're seeing hundreds of thousands of people taking to the streets of Belgrade and just celebrating," he said. "We've seen them dancing, we've seen them singing, drinking."
He added, "There's really a feeling here that the people this time have won their decade-long struggle against President Milosevic."
Thursday's events in Belgrade were welcomed by prominent world leaders.
U.S. President Bill Clinton said, "The people of Serbia have spoken with their ballots, they have spoken on the streets. I hope the hour is near when their voices will be heard and we can welcome them to democracy, to Europe to the world's community.
"And when they do, we will move as quickly as possible to lift the sanctions and build the kind of real partnership that the people there deserve."
Even Milosevic's last ally finally appeared to desert him. Russian President Vladimir Putin declared that he wants to see an end to Yugoslavia's international isolation and for the country to develop along democratic lines.
CNN Belgrade Bureau Chief Alessio Vinci, CNN National Security Correspondent David Ensor, CNN National Security Producer Chris Plante, the Associated Press and Reuters contributed to this report.