Ukraine's fugitive president was indicted for "mass murder" on Monday over the shooting of demonstrators as new leaders in Kiev sought urgent Western aid to make up for a loss of funding from Russia, which is angry at the overthrow of its ally.
Moscow said it would not deal with those who led an "armed mutiny" against Viktor Yanukovich, who was elected in 2010, and said it now feared for the lives of its citizens, notably in the Russian-speaking east and Crimea on the Black Sea.
Russia's top general agreed with NATO to maintain contact on a crisis that has raised fears of civil war and which U.N. chief Ban Ki-moon said called for an "inclusive political process" that "preserves Ukraine's ... territorial integrity".
Meanwhile, European Union foreign policy chief Catherine Ashton arrived in Kiev to discuss measures to shore up the ailing economy, which the finance ministry said needs urgent financial assistance to avoid default.
The EU has contacted the United States, Japan, China, Canada and Turkey to coordinate aid for Ukraine, a senior European Commission official said. France's foreign minister said an international donors' conference was being discussed.
Yanukovych, 63, who fled Kiev by helicopter on Friday, was still at large after heading first to his power base in the east, where he was prevented from flying out of the country, and then diverting south to Crimea, acting interior minister Arsen Avakov said.
"An official case for the mass murder of peaceful citizens has been opened," Avakov wrote on his Facebook profile. "Yanukovych and other people responsible for this have been declared wanted."
Yanukovych had left a private residence in Balaclava, in pro-Russian Crimea, for an unknown destination by car with one of his aides and a handful of security guards, Avakov said.
It was an ignominious political end for Yanukovych who has been publicly deserted by some of his closest erstwhile allies, stripped of his luxury residence near Kiev and had to witness the release from prison of his arch-rival Yulia Tymoshenko.
Russia recalled its ambassador from Kiev for consultations on Sunday, accusing the opposition of having torn up a transition agreement with the president it supported.
Prime Minister Dmitry Medvedev said Moscow had grave doubts about the legitimacy of those now in power in Ukraine and their recognition by some states was an "aberration".
"We do not understand what is going on there. There is a real threat to our interests and to the lives of our citizens," Medvedev was quoted as saying by Russian news agencies.
Russia cited a duty to protect the lives of its citizens in 2008 as one justification for military intervention in Georgia, another former Soviet republic, in support of Kremlin-backed separatists in South Ossetia.
On Independence Square in central Kiev, cradle of the uprising, barricades of old furniture and car tires remained in place, with smoke rising from camp fires among tents occupied by diehards vowing to stay until elections in May.
The mood among the few hundred on the square was a mixture of fatigue, sorrow for the more than 80 people killed last week, and a sense of victory after three months of protests.
A large video screen by the side of the stage was showing the faces of the dead, one after another, on a loop.
"Now is not the time for celebrating. We are still at war. We will stay here as long as we have to," said Grigoriy Kuznetsov, 53, dressed in black combat fatigues.
Galina Kravchuk, a middle-aged woman from Kiev, was holding a carnation. "We are looking to Europe now. We have hope. We want to join Europe, " she said.
A day after Yanukovych fled, parliament named its new speaker, Oleksander Turchinov, as interim head of state. An ally of Tymoshenko, he aims to swear in a government by Tuesday that can run things until a presidential election on May 25.