This report is not confirmed, but it says the president and top aides have fled Kiev. (i also can't confirm that if you click on any of these links you won't get a bad computer virus, so I'm pasting the info below:)
media report that Yanukovych has fled Kiev and has moved to Ukraine's second largest city, Kharkiv. Here is a summary:
Yanukovych, Rybak, Kluyev and Novinsky have flown off to Kharkiv – Media
Viktor Yanukovych, along with a small number of trusted guards, flew off to Kharkiv at 22:40
A source told ZN.UA to a senior source in the presidential administration, reports Tsenzor.NET.