Ukraine's acting government issued an arrest warrant Monday for President Viktor Yanukovych, accusing him of mass crimes against the protesters who stood up for months against his rule. Russia sharply questioned its authority, calling it an "armed mutiny."
Yanukovych himself has reportedly fled to the Black Sea peninsula of Crimea, a pro-Russian area in Ukraine.
Calls are mounting in Ukraine to put Yanukovych on trial, after a tumultuous presidency in which he amassed powers, enriched his allies and family and cracked down on protesters. Anger boiled over last week after government snipers killed scores of protesters in the bloodiest violence in Ukraine's post-Soviet history.
The turmoil has turned this strategically located country of 46 million inside out over the past few days. The parliament speaker is now nominally in charge of a country whose ailing economy is on the brink of default and whose loyalties are sharply torn between Europe and longtime ruler Russia.
Russia and the European Union appeared to be taking opposing sides in Ukraine's new political landscape.
Russian Prime Minister Dmitry Medvedev questioned the legitimacy of the new Ukrainian authorities on Monday. According to Russian news agencies, he said the acting authorities have come to power as a result of an "armed mutiny," so their legitimacy is causing "big doubts."
In Brussels, European Commission spokesman Olivier Bailly referred to parliament speaker Oleksandr Turchinov as the "interim president" and said Turchinov will meet with Monday visiting EU foreign policy chief Catherine Ashton in Kyiv.
Turchinov said he hopes to form a new coalition government by Tuesday.
Ukraine's acting interior minister, Arsen Avakhov, said on his official Facebook page that a warrant has been issued for the arrest of Yanukovych and several other officials for the "mass killing of civilians."
At least 82 people, primarily protesters, were killed in clashes in Kyiv last week.