The nation's embattled president reportedly fled the capital for his support base in Ukraine's Russia-leaning east.
Media outlets reported that President Viktor Yanukovych left Kiev for his native eastern Ukraine after surrendering much of his powers and agreeing to early elections this fall.
The changes came as part of yesterday's deal intended to end violence that killed scores and left hundreds wounded in Kiev this week as snipers opened fire on protesters.
Andriy Parubiy, a leader of the protest camp on Independence Square, known as the Maidan, was quoted by the Interfax news agency as saying that Yanukovych fled for Kharkiv, the center of Ukraine's industrial heartland.
The claims of the president's departure could not be immediately confirmed, however.
Parubiy also said today that protesters are now in full control of the capital. Police yesterday retreated from their positions in Kiev's government district, and the night passed quietly.
Despite significant concessions made by Yanukovych, many of the protesters have remained dissatisfied with the deal and pushed for his immediate ouster.
They booed opposition figures who took to a stage yesterday evening to present the deal, which cuts Yanukovych's powers and calls for early elections but falls short of demands for his immediate resignation.
"Death to the criminal!" some chanted, referring to Yanukovych.
The leader of a major radical group that spearheaded clashes with police, Pravy Sektor, declared yesterday that "the national revolution will continue."
A motion seeking the president's impeachment was submitted late yesterday to the Ukrainian parliament, where members of Yanukovych's faction defected in droves to the opposition side, quickly passing constitutional amendments that trimmed Yanukovych's powers.
It wasn't clear if and when the impeachment motion would be put to vote.
Neither side won all the points it sought in yesterday's deal, and some vague conditions could ignite strong disputes down the road.
The agreement signed yesterday calls for presidential elections to be moved up from March 2015 to no later than December, but many protesters said that is far too late.