The explosion of anger among Odinga loyalists was matched by an outburst of joy in Kenyatta's strongholds from his supporters.
Earlier, Orengo had called for the candidates and observers to be given access to the election commission's computer servers so there could be a transparent audit of data from 41,000 polling stations across the country.
Msgr. Wilybard Lagho, vicar general of the Mombasa Archdiocese, said the election commission had approached the church about offering polling stations, and church officials agreed.
To his rival Odinga, who was not present, he said: "I reach out to you, I reach out to all your supporters, I reach out to all who were elected on now the opposition benches". "And then if they have a concern, go through the rule of law, go to the court process and let the evidence be there for everybody to see".
James Orengo, Chief Election Agent, the opposition coalition, said: "This has been an entire charade".
"We don't want to fight", said Kisumu driver Evans Omondi, 28, wearing a polo shirt and jeans. At least three people were killed amid clashes with police.
Kenyatta's administration has also been plagued by allegations of corruption that many Kenyans see as the reason for the country's vast inequalities, with well-connected millionaires enjoying luxuries while large numbers of people struggle to afford food and housing.
A security source who spoke to the Associated Press said that Raila Odinga had made up his mind to fight to the last.
At Kibera slum in Nairobi, protesters are confronting police in violent protests.
Respondents in a Kenya Ipsos survey said the most serious concerns were high living costs, corruption, a lack of jobs and the drought.
Observers from the African Union and the European Union among others issued a joint statement urging political parties "to use the legally provided channels of dispute resolution in case of any dissatisfaction with the process", adding that police should "avoid excessive use of force".
"When there's some doctoring, I must be anxious".
Protests ensued in Nairobi after Kenya's main opposition leader, Raila Odinga, alleged "massive fraud" after results showed President Uhuru Kenyatta in a clear lead. I'm a Kenyan. I went out and voted peacefully.
He had been heavily criticized throughout his presidency for his failure to grow the job market, which has resulted in staggeringly high rates of unemployment for Kenyan youth. Police used tear gas to prevent the protesters from entering the port city in Kisumu County, where numerous shops opted to stay closed.
He said going to court to challenge the result was not an option, but did not state what measures would be taken.
Previous accusations of election irregularities in Kenya have sparked violence.
Kenyatta, from Kibaki's Kikuyu ethnic group, succeeded him as president in 2013 elections that Odinga also contested and disputed, claiming the government rigged the vote during electronic transmission of results to the central tally center.
Mr. Thabo Mbeki, the former South African President, stressed the need for a peaceful outcome of the Kenyan elections.