Kenya’s incumbent President Uhuru Kenyatta has taken an early lead as votes are counted after Tuesday’s election.
With two thirds of results in he has 55% of the vote against 44% for his rival, Raila Odinga, figures show.
Mr Kenyatta is hoping for a second term in office but faces a tough challenge.
Voting has passed off largely peacefully and the electoral commission has urged people to wait calmly for all the results.
“During this critical phase, we urge all Kenyans to exercise restraint as we await official results from the polling stations and indeed as they start trickling in,” the commission said.
Many fear a repeat of the violence that followed the disputed 2007 election. More than 1,100 Kenyans died and 600,000 were displaced.
Some polling stations remained open after the scheduled 17:00 (14:00 GMT) closing time in areas where heavy rain and other problems had hampered voting.
Despite Mr Kenyatta’s early lead, the BBC’s Tomi Oladipo says it is too early to tell which way Kenyans have voted.
To win outright, a candidate needs more than 50% of the vote, and at least 25% in 24 of Kenya’s 47 counties. If that threshold is not met, a run-off vote between the top two candidates will be triggered.
Voting for the national and local assemblies has also been taking place.