U.S. Secretary of State Colin Powell warns of consequences unless Ukrainian officials investigate instances of fraud in Sunday's presidential election .

The Secretary said the United States can not accept results released earlier Wednesday as legitimate and urged Ukrainian authorities not to use or incite violence against protesters.

Earlier, Ukraine's Central Election Commission declared Prime Minister Viktor Yanukovych the winner of Sunday's presidential election.

Authorities say the prime minister won more than 49 percent of the vote - nearly three percentage points ahead of opposition challenger Viktor Yushchenko.

The announcement Wednesday, came as tens of thousands of protesters continued to mass in the capital, Kiev, alleging widespread fraud in the vote.

Some information for this report provided by AP and AFP.