Ukraine's Supreme Court has invalidated the results of the country's presidential runoff, and called for a repeat vote.

Friday's decision comes as tens of thousands of opposition supporters continue to rally in Kiev over the disputed November 21 poll.

Election officials had declared Prime Minister Viktor Yanukovych the winner of the election, prompting massive demonstrations.

Opposition leader Viktor Yushchenko and international monitors said massive fraud occurred.

Some information for this report provided by AFP and AP.