Ukrainian opposition leader Yulia Tymoshenko has declared that "a dictatorship has fallen" after her release from jail.
The former Prime Minister also declared her intention to run for the Presidency.
But President Viktor Yanukovych remained defiant, saying he was not quitting despite apparently quitting Kiev.
"What's happening now is, to a great extent, vandalism, banditry and a coup d'etat", he said.
Mr Yanukovych has been blocked from taking a plane to Russia, officials have revealed.
Before Parliament voted, Mr Yanukovych reportedly told a local TV station in Kharkiv he would not resign or leave Ukraine, comparing the situation in the country to the Nazis coming to power in 1930s Germany.
Yanukovych was nowhere to be seen as protesters and journalists walked freely through the presidential buildings, tweeting photographs of his bizarre private zoo:
The amazing spectacle had been hidden behind huge walls and never seen by the public.
Matt Frei, of Channel 4 News, described "ornamental lakes, marble statues, deer and antelope cast in bronze."
On Saturday, Parliament voted to remove him from office.
He was reported to be in Kharkhiv, near Russia.
The sudden rush of developments left a power vacuum in the riot-hit country, and rendered pointless the peace deal signed by Yanukovych and the opposition the previous day.
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Ukraine
It comes after the Ukrainian parliament voted in favour of stripping a law that could allow for the release of Tymoshenko, who was defeated in 2010 presidential elections by Yanukovych and imprisoned in 2011 on likely trumped up charges relating to an abuse of office.