Uganda elections: Voting hit by technical glitches amid internet shutdown
Biometric machines - used to verify voters' identity - have malfunctioned in many areas and ballot boxes were undelivered in some polling stations.
Uganda's President Yoweri Museveni admitted even he had problems voting as technical issues disrupted Thursday's election amid an internet blackout.
Museveni, 81, who is hoping to extend his 40-year rule, is widely considered the favourite in the presidential contest. His main challenger is Bobi Wine, a 43-year-old singer turned politician.
In many areas, voting had yet to start hours after polls were due to open as biometric machines - used to verify voters' identity - were malfunctioning and ballot boxes were undelivered.
Some linked the problems to an internet blackout imposed by the government on Tuesday.
Museveni acknowledged even he had trouble and promised to investigate.
"I put my right... thumbprint. The machine did not accept it. I put my left, it did not accept it," he told journalists, adding that the machine finally accepted a scan of his face, allowing him to vote.
There was a heavy security presence in many areas and police have warned the vote is "not a justification for criminal acts".
The government said the internet shutdown was needed to prevent the spread of "misinformation" and "incitement to violence", but the United Nations called it "deeply worrying".
The president said his vote, when it was finally cast, was for anyone "who believes in Uganda... who believes in Africa."