Six policemen were killed in an attack in the coastal city of Mombasa before polling opened but few other incidents were reported during polls seen as key to the regional powerhouse’s stability.
The two favourites are Prime Minister Raila Odinga, who says he was robbed of victory in 2007, and Uhuru Kenyatta, who faces crimes against humanity charges over the violence that killed more than 1,100 people.
Figures released around 10:30 pm (1930 GMT) and based on some 9percent of ballots cast showed Kenyatta with 677,720 votes and Odinga with 481,042.
“All indications are for over 70 percent turnout,” Ahmed Issack Hassan, the head of the Independent Boundaries and Electoral Commission (IEBC), told journalists.
Analysts said that would suggest around 10 million people cast a ballot and that early results provided insufficient information to identify nationwide trends.
The results from the 2007 poll which Mwai Kibaki won against Odinga sparked a wave of protests, notably because of the lack of transparency in the way the tallying was done at that time.
The IEBC said it had decided to immediately make public figures as and when they are sent in by polling stations.
“As soon as data hits our screens it will be made available to the media in real time,” James Oswago, IEBC chief executive officer, told journalists before the numbers started coming in.
Voters standing for hours in snaking lines several hundred metres (yards) long – and several people thick – crowded peacefully outside polling stations to take part in one of the most complex elections Kenya has ever held.
Tension was high Monday on the coast, where six policemen were killed in two separate attacks, including an ambush by some 200 youths armed with guns and bows and arrows, hours before the opening of polling stations.
Polls officially closed at 5pm (1400 GMT), although centres whose opening had been delayed – some for several hours – were to stay open later than planned.
Kenyan police chief David Kimaiyo said the Mombasa attackers were suspected members of the secessionist Mombasa Republican Council (MRC), and that 400 officers were sent to beef up security in the popular tourist region.
Police have blamed the MRC for a string of attacks last year, and the group had threatened to boycott the polls.
Despite the attack, voters packed the streets in the city.
Raphael Zuma said he had waited eight hours to vote in the steamy heat, but happily held up his ink stained finger after finally casting a ballot.
“I had to do it because I wanted to elect new leaders,” he said.
The Kenya National Commission on Human Rights said the attacks “were coordinated and aimed at interrupting voting in these areas.”
A remote-controlled bomb was also set off in Mandera – a town in the north east on the border with war-torn Somalia where Kenyan troops are battling Al-Qaeda linked insurgents – but resulted in no casualties, police said.
At least two other blasts later in the day in Mandera left one person wounded.
Neck-and-neck rivals for the presidency, Odinga and his deputy Kenyatta have publicly vowed there will be no repeat of the bloodshed that followed the 2007 polls.
Crimes against humanity trials later this year at The Hague-based International Criminal Court (ICC) for Kenyatta and running mate William Ruto have raised the stakes: should they win the vote, the president and vice-president could be absent on trial for years.
Both front-runners have said they are confident of winning the absolute majority needed to avoid a second round runoff vote.
“We can win these elections in the first round…” Odinga said after voting in Nairobi’s Kibera shanty town, the scene of some of the worst ethnic clashes after the 2007 poll.
Kenyatta, voting in his hometown of Gatundu some 90 kilometres (55 miles) north of Nairobi, said he was “ready and prepared for whatever outcome” Kenyans chose.
Kenyans cast six ballots, voting for a new president, parliamentarians, governors, senators, councillors and special women’s representatives.
The 2007-2008 violence exposed deep tribal divisions and widespread disenchantment with the political class and shattered Kenya’s image as a beacon of regional stability.
More checks are in place this time to limit vote rigging, while a new constitution devolving powers has made the poll less of a winner-take-all race.