A little more than 19 million Kenyans are eligible to vote in a closely-fought election in which sitting President Uhuru Kenyatta is pitted against veteran politician Raila Odinga. In some parts of the country, voters lined up outside polling stations at 3am, hours before booths officially opened.

The contenders have called for a peaceful vote amid widespread fears that the crucial election could be marred by communal violence. This is the young East African nation's 11th election since its independence from Britain in 1963. The turnout in the 2013 election was more than 86%.

Kenyatta, 55, is seeking his second and final five-year term as his long-time rival, Odinga, 72, is putting up a stiff fight. Kenyatta, son of the country's founding father, is hopeful of securing another term as no sitting president has lost an election in the past in Kenya. Odinga is seeking the presidential office for the fourth time.

Campaigning for the election has been hectic with charges of plots to rig the vote flying thick and fast. Employment, the economy and handling of corruption are the main issues in the election.

The results are expected to be announced within seven days of polling. One of the presidential candidates needs to win at least 50% of the total votes and a minimum of 25% of votes in 24 of 47 counties to avoid a run-off. Both Kenyatta and Odinga have been appealing to young voters as the majority of registered voters are under the age of 35.

Odinga, who was defeated in the 2013 election by Kenyatta, questioned the legitimacy of the electoral outcome and the matter had to be settled by the Supreme Court.

"After you cast your ballot, please go home. Go back to your neighbour. Regardless of where he or she comes from, their tribe, their colour or their religion. Shake their hand, share a meal and tell them 'let us wait for the results,' for Kenya will be here long after this general election," Kenyatta said in a televised address on the eve of polling day.

Kenya presidential elections
People queue to cast their vote at a polling station during the presidential election in Kibera, Nairobi, KenyaThomas Mukoya/Reuters