Kenyan President Uhuru Kenyatta was on Friday declared the victor of Tuesday's presidential elections with 8.20 million (54.27 percent) votes against 6.76 million (44.74 percent) for his main challenger, Raila Odinga after a tense electoral process which was preceded by an opposition walkout.
Mr. Odinga, 72, the opposition leader, received 44.7 percent of the vote.
But Kenyan election officials say only they have the authority to declare the victor, and worldwide election observers say they have seen no signs of interfering with the vote.
Worldwide observers on Thursday praised the handling of the election, with the European Union mission saying it had seen no sign of manipulation despite opposition complaints and scattered protests.
But Odinga supporters, many of them members of his Luo tribe or other allied tribes, said they are being robbed of yet another election.
IEBC chairman Wafula Chebukati said a total of 15,073,662 voters took part in the elections.
"I therefore declare Hon".
He first alleged that a hacker had gained access to the electoral commission's database and then accused the commission of concealing the actual results, which Odinga said proved he was the victor.
Odinga contested and lost Kenya's last two elections, which he also said were rigged.
"If anything was electronically fiddled with, there is a way to go back and absolutely ascertain what happened in the polling station", he said.
The Chairperson of the AU Commission visited Kenya ahead of the polls on July 18-20 this year, during which he called for peaceful and credible elections before, during and after the elections, recalled the statement.
Police fired tear gas at rock-throwing opposition supporters in one Nairobi neighbourhood, residents said, but most of the capital and the rest of the country were calm after four people were killed in election-related violence on Wednesday.
"Nobody should think that this is the end of the matter", he said.
In 2007, tallying was halted and the incumbent president declared the victor, triggering an outcry from Odinga's camp and waves of ethnic violence that led to International Criminal Court charges against Kenyatta and his now-deputy, William Ruto.
He said the opposition's own informal vote tally gave him 8.1 million votes compared with 7.2 million for Kenyatta.
Top opposition official James Orengo denounced the vote counting process as a "charade".
The election commission has until August 15 to release the final tally.
Opposition candidate, Raila Odinga, whose rejection of the 2007 presidential election result triggered widespread bloodshed, has challenged the results released so far.
There have already been sporadic clashes between police and protesters in Nairobi's slums and in opposition strongholds in western Kenya. Many businesses remain closed amid fears of violence. But it has been battered by terrorist attacks, including one on an upscale Nairobi mall that killed 48 people in 2013, and another in 2015 at a northern university, which left 148 dead.