Ukrainian news agencies, citing the deputy head of the State Border Service, reported that a chartered airplane with Yanukovych onboard was denied permission to take off from Donetsk, a city in eastern Ukraine that is the president's base of support.
The centre of Kiev, meanwhile, was calm as the sun came up today after a day that saw a stunning reversal of fortune in Ukraine's political crisis.
Protesters yesterday took control of the presidential administration building, and thousands of curious and contemptuous Ukrainians roamed the suddenly open grounds of the lavish compound outside Kiev where Yanukovych was believed to live.
Parliament, which he controlled the previous day but is now emboldened against him, called for his removal and for elections on May 25.
But Yanukovych said he now regards the parliament as illegitimate and he won't respect its decisions. The political crisis in the nation of 46 million, strategically important for Europe, Russia and the United States, has changed with blinding speed repeatedly in the past week.
First there were signs that tensions were easing, followed by horrifying violence and then a deal signed under Western pressure that aimed to resolve the conflict but left the unity of the country in question.
Tymoshenko, whose diadem of blond peasant braids and stirring rhetoric attracted world attention in the 2004 Orange Revolution, was both sad and excited as she spoke to a crowd of about 50,000 on Kiev's Independence Square, where a sprawling protest tent camp was set up in December.
Sitting in a wheelchair because of a back problem aggravated during imprisonment, her voice cracked and her face was careworn.
But her words were vivid, praising the protesters who were killed this week in clashes with police that included sniper fire and entreating the living to keep the camp going.