By Duncan Miriri and Rajiv Golla
NAIROBI (Reuters) - Kenya's president took an early lead as results from national polls rolled in Wednesday, the election board said, but the opposition dismissed the numbers as "fake" and said their own tally showed they were winning.
Tuesday's contest between President Uhuru Kenyatta, a wealthy 55-year-old businessman, and Raila Odinga, 72, a former political prisoner and self-described leftist, was a hard-fought election that stoked fears of possible violence.
Kenyatta was leading with 55 percent of the vote and Odinga had 44 percent at 3.00 am (0000 GMT), the election commission website said, after nearly three-quarters of polling stations had reported results.
But Odinga angrily dismissed that tally as "fictitious ...fake" at a late-night press conference and said the results were a sham because they were not accompanied by scanned copies of forms that party observers in all polling stations should have signed to certify the results.
Kenyan law states where there is a discrepancy between a result on the website and the form, the result on the form will be considered final.
"We have our projections from our agents which show we are ahead by far," Odinga said, questioning why Kenyatta had maintained a fairly static lead since tallying began. He also linked his allegations of vote rigging to the unsolved torture and murder of a top election official days before the vote.
"We fear this was exactly the reason Chris Msando was assassinated," he said.
Odinga's comments could spark protests by his followers, as happened in 2007 when he cried foul after losing an election that was marred by major irregularities. Around 1,200 people were killed in the violence that followed.
Odinga also ran and lost in 2013, but quelled potential clashes by taking his complaints about the widespread failure of electronic voting equipment to court.
Many Odinga supporters said they believed their leader had been robbed of victory during the last two polls and vowed not to allow a third election to be stolen from them.
"I will accept the outcome only if it's credible," said Odinga supporter Joseph Okuoch as he carefully watched vote tallying at his polling station in Kisumu.
Odinga, the son of Kenya's first vice-president, comes from the Luo people in western Kenya, an area that has long felt neglected by the central government and resentful of their perceived exclusion from power.
Kenyatta, the son of the first president, is a Kikuyu, an ethnic group that has supplied three of Kenya's four presidents since independence from Britain in 1963.
On Tuesday, Kenyatta called on whoever lost to concede the race.
"In the event that they lose, let us accept the will of the people. I am willing myself to accept the will of the people, so let them too," Kenyatta said as he voted at the Mutomo Primary School in Gatundu, some 30 km (20 miles) north of the capital.
Later, Odinga also told German broadcaster Deutsche Welle that he would also accept loss, "in the unlikely event that I lost fairly".
The winner needs one vote more than 50 percent, and at least a quarter of the vote in 24 of Kenya's 47 counties.
In addition to a new president, Kenyans are electing lawmakers and local representatives, the result of a 2010 constitution that devolved power and money to the counties.
(Additional reporting by Maggie Fick in Kisumu; writing by Katharine Houreld; Editing by Andrew Hay)