Nairobi - The Latest on Kenya's elections (all times local):
In Kenya's Kisumu city, voters have different views about the possibility of violence if there is a dispute over the results of the presidential election.
"If the elections are not fair, if there was rigging, people will definitely go to the streets," said Sophia Ajwang, a 29-year-old student.
However, Moses Otieno, a 33-year-old businessman, predicted that Kenyans don't want to see the kind of deadly, ethnic-based violence that erupted after the 2007 vote.
"We've learned a lot in the past, so we don't want such repetition in this election," Otieno said. "That's why we will accept whatever outcome it is."
Former US Secretary of State John Kerry, who is observing Kenya's elections, is calling for patience and says eventual vote-counting will be critical to the success of the process.
"There are a lot of people in line, and it is going to take some time, and we are going to need to be very patient," said Kerry, chief election observer for The Carter Center. "But obviously, the transition from voting to counting is going to be critical and there is a process in place for that too. That's why it is too early for us to be drawing any kinds of conclusions, but we will see where it goes."
Kerry said that his team will be talking to election officials and other observers and that "over the course of the next day and a half, two days, solid judgments will begin to be made."
Kenyan President Uhuru Kenyatta has voted in his birthplace of Gatundu, north of Nairobi.
Kenyans on Tuesday started voting in a fiercely contested election that pits Kenyatta against challenger Raila Odinga. This East Africa economic hub is known known for its relative, long-term stability as well as vying ethnic allegiances that shadow its democracy.
"I feel good. I feel positive because we ran a positive campaign," Kenyatta said after casting his vote. He urged Kenyans to vote peacefully and go home to await the results. He was accompanied by his wife, Margaret, his mother and two of his three children.
"Peace. Peace. Peace," said Kenyatta, who seeks a second and final term in office. "I say peace because Kenya was here before and it will be here after today."
Raila Odinga, the main opposition challenger in Kenya's tightly-contested election, has voted.
Odinga, 72, voted in the poor area of Kibera, an opposition stronghold in the capital, Nairobi, and was surrounded by well-wishers. He urged supporters to gather on Wednesday in a downtown park for what he predicted would be a celebration.
"Uhuru must go," chanted some in the crowd, referring to President Uhuru Kenyatta, who seeks a second term in office.
A Kenyan legislator who supports Raila Odinga, the main opposition leader running for president, says he is worried about some flaws in the voting process in Kenya's hotly contested elections.
Kenyan are voting on Tuesday in the elections pitting Odinga against President Uhuru Kenyatta.
"We hope the counting process will be as good as the voting and the results will reflect the true winner," said Ken Okoth, legislator for the Kibera constituency in Nairobi.
"There is concern over voter registration where people who corrected mistakes of their details cannot find their names on the list. I estimate between 500 and 1 000 people are affected by this," he said.
Okoth called for vigilance, saying it brings credibility to the elections.
An international election observer says Kenyans are voting with enthusiasm and that the process is going well.
John Mahama, chief election observer for the Commonwealth and former president of Ghana, said early on Tuesday that he is impressed by the voter turnout.
"There have been no incidents so far," Mahama said. "Voting seems to be going smoothly and I think it is a good sign for Kenyan democracy."
Kenya has 20 million registered voters out of a population of more than 40 million people. They are voting in a fiercely contested election that pits President Uhuru Kenyatta against challenger Raila Odinga.
A 102-year-old woman believed to be one of Kenya's oldest citizens said she has voted for incumbent president Uhuru Kenyatta.
Lydia Gathoni voted in Kenyatta's home town, Gatundu, north of Nairobi.
"I have come here to vote because good leadership comes from God. I want to vote because I believe God has kept me alive for so many years," said Gathoni.
Kenyans on Tuesday started voting in an election that pits Kenyatta against challenger Raila Odinga in this East African economic hub known for its relative, long-term stability as well as the ethnic allegiances that shadow its democracy.
Election officials say the winner of Kenya's presidential race must get more than 50% of the votes as well as one-quarter or more votes in at least 24 of Kenya's 47 counties. If the front-runner falls short of those benchmarks, the two top contenders will contest a run-off vote.
President Uhuru Kenyatta and challenger Raila Odinga also faced off in the 2013 election. Kenyatta won by a thin margin, with just over 50% of the vote; Odinga alleged vote-tampering and took his case to Kenya's highest court, which ruled in Kenyatta's favor by validating the results.
Like many Kenyan voters, 34-year-old Fred Nyakundi arrived at a polling station several hours before it opened and waited in line in the dark before casting his vote.
"The exercise is very slow, but I am happy with the service I got," said Nyakundi, who owns a carpentry business in Nairobi. "I am going home to open the business and wait for results."
Another voter, 41-year-old Fatuma Ramadhan, thought the voting procedure was speedy. She was able to vote at 06:00, when polling stations opened, and then opened her restaurant to serve breakfast to other voters.
Early voters went to the polls across the country at sunrise. Election officials say the polls will close at 17:00 (10:00 Eastern Time, 14:00GMT). Vote counting will start immediately and results are expected within 24 to 48 hours, although authorities have up to a week to deliver official, final results.
Kenyans are voting in an election that pits President Uhuru Kenyatta against challenger Raila Odinga in an East African economic hub known as much for its relative, long-term stability as the ethnic allegiances that shadow its democracy.
A key concern after polls opened on Tuesday was whether Kenya would echo its 2013 election, a mostly peaceful affair despite opposition allegations of vote-tampering, or the 2007 election, which led to violence fueled by ethnic divisions that killed more than 1 000 people.
Reaction to the result could partly depend on the performance of Kenya's electoral commission, which will collect vote counts from more than 40 000 polling stations. Kenya has nearly 20 million registered voters.
Former US Secretary of State John Kerry is among thousands of observers who are monitoring the election.