Vote counting has begun in Kenya's general election after a turnout of more than 12 million kept some polling stations open beyond the official time.
Voters on Monday remained queued past the 14:00GMT deadline. Many waited for more than six hours at a time to cast ballots for a president, senators, members of parliament, county governors and representatives to the newly formed county assembly.
The general election marks the first vote since deadly ethnic violence that killed more than 1,200 people following disputed polls in 2007.
Turnout topped 70%, the head of the Independent Boundaries and Electoral Commission said late on Monday.
"All indications are for over 70% turnout," Ahmed Issack Hassan told journalists, saying he would announce a more accurate figure later.
The ODM party of Raila Odinga, outgoing prime minister, has expressed its disatisfaction with certain elements of election conduct.
Franklin Bett, party spokesman, said that at some polling stations electoral officials had to identify voters manually. That may have led to some ghost voters or people casting their ballot twice.
Speaking to Al Jazeera, Bett clarified that he was "simply saying these shortfalls may have given an opportunity to people to manipulate the vote. It is not necessarily that the IEBC is abetting it is that irregularity and that shortfall in functions of the IEBC may have given an opportunity to certain individuals bent on rigging."
The two rivals for the presidency, Odinga and Uhuru Kenyatta, deputy prime minister, have publicly vowed that there would be no repeat of the violence, which displaced more than 600,000 people.
With 14 million registered voters heading to the polls, a police spokesman said that 99,000 officers were deployed to avert a repeat of deadly violence in December 2007.
But just before the polls officially opened, police in the coastal city of Mombasa reported night time raids by machete-wielding gangs who ambused officers.
Al Jazeera's Nazanine Moshiri reports from the capital Nairobi
At least 19 people were killed in an incident in the coastal city, including six police officers.
Sources reported that it was the work of the Mombasa Republican Council, a secessionist group on Kenya's coast.
Al Jazeera's Peter Greste, reporting from Kisumu, said the situation in Mombasa cannot be extrapolated to the rest of the nation.
There is "a very volatile situation on the coast. Mombasa is a very, very specific situation," he said.
The MRC has denied responsibility for the coastal violence.
In Kilifi, a gang assaulted security forces at a school which was being used as a voting centre. At least four officers were killed.
The police said late on Sunday that criminals were planning to dress in police uniforms and disrupt voting in some locations.
About 23,000 observers, including 2,600 international monitors, will be deployed, according to the Independent Electoral and Boundaries Commission.
But watchdogs such as Human Rights Watch have warned that the risk of renewed political violence is "perilously high." Many Kenyans have left the cities to wait out the vote in their home villages.
Trials are expected to start later this year at the International Criminal Court for Kenyatta and his running mate, William Ruto. If they win, the president and vice president could be absent on trial for years.
Tens of thousands of party loyalists roared their support as Kenyatta and Odinga held competing rallies in central Nairobi on Saturday in the closing hours of campaigning.
'Peace, love and unity'
Both men have voiced confidence of securing an absolute majority, necessary to avoid a second-round runoff, although with eight candidates in the race many expect a further vote next month.
"I want to promise you that we will change Kenya for the better," said Kenyatta, dancing on stage alongside Ruto.
"Bring even the sick to vote," urged Odinga in turn, after releasing a white dove to symbolise peace.
The electoral commission will have seven days to announce the results.
The 2007-2008 violence exposed widespread disenchantment with the political class and deep tribal divisions.
More checks are in place this time to limit vote rigging, while a new constitution devolves powers and has made the poll less of a winner-take-all race.