Updated

The whereabouts of Ukrainian President Viktor Yanukovych are unclear, a day after he left the capital and his arch-foe Yulia Tymoshenko was freed from prison and returned to Kiev to address a massive, adoring crowd.

Ukrainian news agencies, citing the deputy head of the State Border Service, report 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 center of Kiev, meanwhile, was calm as the sun came up Sunday after a day that saw a stunning reversal of fortune in Ukraine's political crisis.

Protesters took control of the presidential administration and parliament called for Yanukovych's removal. The president, however, has vowed to remain in power.