Ugandan police have fired tear gas to disperse furious voters in the capital, Kampala, as the election commission apologised for hours-long delays in delivering ballot papers, AFP reporters said.
Voting was due to begin on Thursday at 07:00am local time (04:00 GMT), but was stalled for several hours in some polling stations in the city and surrounding Wakiso district when ballot boxes and papers did not arrive on time.
Kampala traditionally shows strong support for the opposition.
Veteran leader Yoweri Museveni is widely expected to win a fifth term, extending his power into a fourth decade, since he seized power in 1986.
Election commission spokesman Jotham Taremwa said: “There was a bit of a delay at some polling stations because of logistical problems.”
At one Kampala polling centre, hundreds of frustrated voters shouted and gesticulated at election officials.
“They are denying us our constitutional right,” said Elias Bukenya, a 27-year-old teacher who suspected foul play.
I dodged the apparent shutdown using virtual private networks.
The government regulator, the Uganda Communications Commission, said the attempted shutdown was for “security reasons” without giving details.
Initial results are expected as early as Saturday afternoon, with the leading candidate requiring more than 50 percent of votes cast to avoid a second round run-off.
More than 15 million people are registered to vote, casting ballots in more than 28,000 polling stations for both a president and members of parliament, with 290 seats being contested by candidates from 29 political parties.