Anti-government protesters sing the Ukrainian national anthem at Independence Square in central Kiev. Ukraine's leader and opposition on Friday signed a deal to end the splintered country's worst crisis since independence after three days of carnage left nearly 100 protesters dead.

Feb. 22, 2014 Anti-government protesters sing the Ukrainian national anthem at Independence Square in central Kiev. Ukraine's leader and opposition on Friday signed a deal to end the splintered country's worst crisis since independence after three days of carnage left nearly 100 protesters dead. Louisa Gouliamaki/AFP/Getty Images

Thousands of protesters descended on the presidential residence amid reports that President Viktor Yanukovych had fled and public documents were being destroyed. The Ukrainian parliament voted Saturday evening to dismiss Yanukovych from office

Thousands of protesters descended on the presidential residence amid reports that President Viktor Yanukovych had fled and public documents were being destroyed. The Ukrainian parliament voted Saturday evening to dismiss Yanukovych from office

Thousands of protesters descended on the presidential residence amid reports that President Viktor Yanukovych had fled and public documents were being destroyed. The Ukrainian parliament voted Saturday evening to dismiss Yanukovych from office

The foes of ousted president Viktor Yanu­kovych took swift, bold action Sunday to consolidate power and transform the government, sacking ministers, freeing jailed protesters and announcing detentions of former officials, even as ordinary Ukrainians confessed they weren’t really sure who was running the country or where it was headed.

By decree, the nation’s parliament gave interim presidential authority to the speaker, Oleksandr Turchynov, a leader of the opposition.

Turchynov quickly delivered some sobering news: The economy was in a shambles, and the government coffers empty. Ukraine’s pension fund, currency and banking system were facing “immense problems,” he said, according to the news agency RIA Novosti.

Sunday’s actions brought the latest dramatic changes to a country convulsed by protests since Yanukovych reversed course on a trade agreement with the European Union three months ago and turned to Russia for economic aid. Since then, 88 people have died in demonstrations and clashes with riot police and security forces, which culminated in the president’s removal in a parliamentary vote on Saturday .

Even as demonstrators in Kiev celebrated Sunday, there were signs of trouble in parts of Ukraine that lean more toward Russia than Europe. In the southern Crimean region, men gathered to volunteer for militias to oppose the decrees announced in the capital.

There has been no word from Yanukovych since a short pre­recorded interview aired Saturday morning on Ukrainian television, in which he blasted his removal as “illegal” and refused to resign. Border police said they stopped his plane in Donetsk on Saturday as he was trying to leave the country.

The interim Ukrainian interior minister stated that an warrant for Yanukovych’s arrest was issued, the Associated Press reported early Monday.

Yanukovych’s whereabouts remain unknown, even to members of his party.

Legislators said Sunday that they urgently needed to form an interim unity government, leading up to elections they have called for May 25. But in their rush, they got ahead of themselves.

The lawmakers put forth the name of former prime minister Yulia Tymoshenko as a possible candidate for the premiership. But she quickly said she was not interested in the job and hadn’t been consulted.

Even Yanukovych’s allies began to turn against their former boss on Sunday, blaming him for the crisis.

Oleksandr Yefremov, a leader of Yanukovych’s Party of Regions, said he “strongly condemns the criminal orders that led to human victims, an empty state treasury, huge debts and the shame before the eyes of the Ukrainian people and the entire world.”

Vitali Klitschko, an opposition leader in parliament, said: “Millions of Ukrainians want to know where is the president. He’s disappeared. So we have a new one.”

The White House found itself in the dark as well. “He’s gone,” national security adviser Susan E. Rice said Sunday on NBC’s “Meet the Press.” “He took his stuff, his furniture with him. . . . Yesterday we knew where he was; today we’re not so sure.”

Rice said that the Ukrainian economy was “very, very fragile” and that the U.S. government would work with the International Monetary Fund on assistance. E.U. officials also have indicated that they are ready to offer financial aid to the new government.

On Sunday, Treasury Secretary Jack Lew spoke by phone with opposition leader Arseniy Yatsenyuk and told him of the broad support expressed at the just-

concluded Group of 20 meeting for an international assistance package for Ukraine centered on the IMF. But Lew stressed that the transitional government must first be fully established.

Concerns and chaos

Ukraine’s interim government faces huge problems, even beyond the teetering economy.

“There are no police on the streets right now,” Klitschko told reporters. “The police will be reorganized, and we will try to do this as fast as possible.”

Another member of parliament warned his colleagues that they needed to work quickly to bring Ukraine’s security forces back to work, saying that some of the nation’s vital infrastructure, including nuclear power plants, was unguarded.

Opposition leaders urged thousands of demonstrators still in Kiev’s Independence Square to remain where they are to guarantee that the government changes wouldn’t be reversed.

They called upon the “self-

defense” militias organized to defend the barricades at the square to remain on the streets to provide security. Groups of men in mismatched military uniforms, wielding baseball bats and homemade shields, were directing traffic at intersections and standing guard in front of government offices.

On Sunday, Independence Square was filled with Ukrainians who piled heaps of flowers at makeshift shrines beside photographs of protesters killed in the most recent clashes. In western Ukraine, which is fervently pro-Europe, large crowds assembled to mourn protesters slain in the past week.

Members of the opposition announced that protesters arrested during the demonstrations would be freed immediately, while they also sought to detain and prosecute the dismissed prosecutor general, Viktor Pshonka.

The interim interior minister, Arsen Avakov, promised that the government would open an inquiry into the use of lethal force by riot police and security forces.

Tymoshenko was released from a prison hospital Saturday, after serving 30 months in jail for what her supporters — and Western governments — say were politically motivated charges of embezzlement and abuse of power surrounding a deal to buy natural gas from Russia.

Many Ukrainians had assumed that she would be a candidate in the May elections. She lost to Yanukovych in the presidential race in 2010.

Focus on Russia’s role

Among the unknowns Sunday was how Russia would react to the swift change in Ukraine, a former Soviet republic that Moscow regards as a vital strategic interest. In December, Russia had signed a deal with Yanukovych promising a $15 billion support package for Ukraine. The move toward Russian aid fueled the protests in Kiev.

Russian President Vladimir Putin and German Chancellor Angela Merkel spoke by telephone Sunday about the developments in Ukraine, according to the Interfax news agency. The E.U. foreign affairs chief, Catherine Ashton, is scheduled to arrive in Kiev on Monday. William Hague, the British foreign secretary, told the BBC on Sunday, “We don’t know, of course, what Russia’s next reaction will be.”

Russian officials have criticized the Ukrainian opposition for signing and then reneging on a compromise deal reached last week with Yanukovych that would have allowed him to stay in power for 10 more months and then pushed him aside.

“We do know that Russia, as well as the United States, has said a few days ago that they would get behind a deal that had been made. That deal has now been overtaken by events, and this is the importance of us continuing a dialogue with Russia,” Hague said.

Russian Finance Minister Anton Siluanov said Moscow would delay a planned purchase of $2 billion in Ukrainian eurobonds until Kiev formed a new government.

Ukraine’s parliament delighted many citizens by announcing Sunday that the government would confiscate the ousted president’s opulent estate on the outskirts of Kiev.

On Sunday, thousands of Ukrainians continued to tour the grounds, ogling at Yanukovych’s collection of classic cars, a restaurant in the shape of a full-size Spanish galleon, a golf course and zoo animals.

Meanwhile, journalists were poring over a trove of documents found dumped in the Dnieper River that flows past the compound.

Karen DeYoung in Washington contributed to this report.