Burundians voted on Wednesday in their first competitive presidential election since a civil war erupted in 1993.
The election commission called for a peaceful vote despite simmering political violence and the coronavirus pandemic.
President Pierre Nkurunziza, whose government has repeatedly been accused of rights abuses, will step down after 15 years.
His ruling CNDD-FDD party candidate, retired army general Evariste Ndayishimiye, is running against opposition leader Agathon Rwasa and five others.
The government expelled the national head of the World Health Organization last week following public criticism that all parties were holding rallies despite the disease.
“We call on Burundians to vote in massive numbers and vote peacefully. We need good elections,” Pierre Claver Kazihise, chairman for the election commission said on state broadcaster RTNB.
In the commercial city of Bujumbura, a Reuters witness said lines were long in the morning in Musaga neighbourhood, where the opposition is popular.
“The voting is really taking place smoothly and I voted for change but I am pessimistic about the counting of votes,” said one resident who did not wish to be named.
First democratic transition
Several voters were worried that Twitter and WhatsApp – messaging services that can spread information quickly – seemed to be shut down.
The election is meant to usher in the first democratic transition in 58 years of independence for the impoverished east African nation, after widespread international criticism of its last election.
Nkurunziza won a third term in the controversial elections of 2015.
His opponents said his participation violated a peace deal that ended the civil war and boycotted the poll.
That election sparked violent protests that drove hundreds of thousands of Burundians into exile.
The United Nations documented hundreds of killings and the torture and gang-rape of opposition activists. Donors withdrew funding.
The government denies accusations of rights violations.
Rwasa, like Nkurunziza a former rebel leader, warned about possible electoral fraud on Sunday.
Intimidation and violent clashes
“We know there is plan of election fraud, some are even intimidating people asking for their voter cards to vote for them,” he said.
The United Nations and the African Union are “concerned about reports of intimidation and violent clashes between supporters of opposing sides”.
There will be few international election monitors after the government said they would have to quarantine for 14 days to prevent the spread of the coronavirus.
Full results are expected within a week – if no one wins 50% in the first round then a run-off is held within a fortnight.
Burundi has reported 42 coronavirus cases and one death.
But only 633 tests have been carried out, according to the Africa Centres for Disease Control and Prevention.