Ukraine's ousted president Viktor Yanukovich is now wanted by police for mass murder, the acting interior minister has posted on his Facebook profile.
"An official case for the mass murder of peaceful citizens has been opened. Yanukovich and other people responsible for this have been declared wanted," Arsen Avakov wrote on Monday morning, translated by the Kyiv Post.
Yanukovich is believed to be in Ukraine's Russian-leaning east, but has not been seen since the weekend.
European Union foreign policy chief Baroness Ashton is due to visit Kiev today to meet key players in the drama, her office said.
Lady Ashton will discuss the EU's support for a lasting solution to the political crisis and measures to stabilise the economic situation.
With Yanukovich refusing to accept the will of the country's MPs, fears mounted that it could split in two - a Europe-leaning west and a Russian-leaning east and south.
He has insisted he is the "legitimately elected president" and had been the victim of "banditry and a coup d'etat".
Ukraine's parliament voted to temporarily hand the president's powers to speaker Oleksandr Turchinov, a close ally of former prime minister Yulia Tymoshenko.
After spending two-and-a-half years in prison, Tymoshenko addressed the protest movement in Independence Square, but has asked not to be nominated for the post of prime minister in the new administration being formed.
It is thought she may want to focus her energies on campaigning for president, where she could face former heavyweight boxing champion Vitali Klitschko.
"I want to make Ukraine a modern European country," the boxer turned political leader told the BBC. "If I can do that through the president's position, I will do my best."
Foreign Secretary William Hague is due to speak to his Russian counterpart on Monday, having warned that it would not be in Russia's interests to intervene militarily in the crisis on its borders amid fears that Moscow could send in troops.
The Foreign Secretary said there was a "moment of opportunity" in Ukraine after MPs voted to oust Yanukovich and hold fresh elections in May, but acknowledged there were "still many dangers" for the country.
He said: "It's very important for us to try to persuade Russia that this need not be a zero sum game.
"It's in the interests of the people of the Ukraine to be able to trade more freely with the European Union, it's in the interest of the people of Russia for that to happen as well.
"We are in constant discussion with Russia and it's very important we keep that up, particularly if there's an economic package, it will be important that Russia doesn't do anything to undermine that economic package and is working in co-operation and support of it.
"So, a lot of work to do with Russia over the coming days."