Official election staff in Zimbabwe said today opposition leader Morgan Tsvangirai won the presidential election but with only 47.9% of the vote, meaning a run-off ballot must be held.
The Electoral Commission said that current president Robert Mugabe won 43.2% of the votes.
It said it would announce a date for the run-off election later.
The commission had long delayed today’s announcement of the results from the March 29 election.
Mr Tsvangirai claims he won the vote outright and will not campaign in a run-off.
He says that Mugabe has used the delay to prosecute a campaign of violence to scare voters from further opposing his rule.
Mr Tsvangirai's Movement for Democratic Change party had challenged the count even before the results were released, over 120,000 unaccounted votes that could give him outright victory.
Officials from the MDC and Mugabe’s ruling ZANU-PF party had been asked to confirm the Electoral Commission’s tally as part of the verification process.
But earlier today, an MDC spokesman said they anticipated needing another three or four days to examine the verification of the results.
“We just said to the electoral commission we’re not moving forward until we understand where these 120,000 votes came from,” he said.
The opposition and rights groups also have accused Mugabe of deliberately withholding the presidential results for more than a month to buy time to intimidate voters.
Independent rights groups said post-election violence makes it unlikely a runoff could be free and fair.
Mugabe, who has been in power since Zimbabwe gained independence from Britain in 1980, has been accused of brutality and increasing autocracy.
But the main campaign issue for many here had been the economic collapse of what had once been a regional breadbasket.