The opposition leader said hackers broke into Kenya's election commission computer systems and database overnight, leading to "massive and extensive" vote fraud that nullified the published victory of President Uhuru Kenyatta.
Security sources in Kenya have told Saharareporters that Kenya's opposition leader, Raila Odinga is determined to take Kenya down with him if the Independent Electoral and Boundary Commission (IEBC), declares presidential election results that do not have him declared as the victor of last Tuesday's Presidential election.
Demonstrators protesting the result in Kisumu, western Kenya, say police are shooting at them and using tear gas.
Opposition supporters in Kibera have burned tires and shouted slogans, hours after clashes between police and protesters erupted in Kawangware, another poor area of the capital.
"Hacking was attempted but did not succeed", election commission chairman Wafula Chebukati told a news conference.
The hacking claims prompted Kenya's Election Commission to react and counter the allegations, assuring Kenyans that "all is well".
The opposition, in asking for access to the election commission's servers, said it will accept the results even if they show Kenyatta won.
"There were no external or internal interference to the system at any point before, during or after the voting", he added, amid repeated calls for calm.
An opposition supporter during demonstration in Nairobi
Mr Odinga said the results were the "work of a computer" and did not reflect the will of voters.
"We do not want to see any violence in Kenya", he said.
Mr. Odinga had so far received 44.8 per cent.
"Elections should never be an issue of life or death", said Marietje Schaake, the Dutch head of the European Union mission observing the elections. "We commend the IEBC for ensuring that overall law and order prevailed throughout the electoral process observed", said Rugumayo.
He added: "I wish to take this opportunity to confirm that our elections management system is secure".
Mr Kenyatta was leading with 54.34 per cent and Mr Odinga had 44.78 after votes at almost 39,000 of the 40,883 polling stations were counted, according to the Kenya's election commission.
Hundreds of police in anti-riot gear are patrolling Nairobi's central business district and opposition strongholds.
The electoral commission said it was not prepared to dismiss Odinga's claim outright. The 2007 election was followed by violence fueled by ethnic divisions that killed more than 1,000 people. He also lost the 2013 vote to the 55-year-old Kenyatta and took allegations of vote-tampering to the Supreme Court, which rejected his case.