Bobi Wine, a 38-year-old musician, is the frontrunner seeking to replace long-time leader Yoweri Museveni, who eyes a sixth term. Voters headed to the polls amid an internet blackout.
Vote counting was underway after the polling stations closed in Uganda, with results expected by Saturday. The winning candidate must pick up more than 50% of ballots to avoid a runoff vote. Nearly 18 million people are registered voters in this East African country of 45 million people.
The 38-year-old Bobi Wine, whose real name is Robert Kyagulanyi, said the 76-year-old president could not offer Ugandans the change they want after 35 years in power amid high unemployment and ballooning public debt.
President Museveni, without offering any evidence, has said Wine is backed by foreign governments, as well as homosexuals.
The former guerrilla fighter, who helped oust dictator Idi Amin in 1986, changed the constitution to run for a sixth five-year term.
Internet blackout caused delays
DW's Julius Mugambwa, reporting from Kampala, said there were delays to the start of voting on Thursday in the Ugandan capital, Kampala.
"The main reason given out was that the biometric system supposed to be used by the electoral commission has also been affected by the internet blackout," he said.
Mugambwa reported that Wednesday's web shutdown has made it difficult to find out what is happening in other parts of the country.
Many voters had relied on social media for information in the midst of the coronavirus pandemic.
"That has compromised the need to monitor the situation elsewhere," he said.
Wine took to Twitter late on Wednesday to hit out at the internet blackout, branding Museveni a "dictator".
Voters hungry for change
Joseph Kinobe, 40, a mason who was waiting to cast his ballot for Wine, said he was desperate for change.
"I'm tired of Museveni because he has no new ideas," he was quoted as saying by Reuters.
"I am here to change the leadership of this nation because for years, they've been telling me they will secure my future. They have not done that," driver Joseph Nsuduga, 30, told AFP news agency in the opposition heartland of Kamwokya.
The hotly contested presidential vote, which took place at the same time as parliamentary elections, has been accompanied by a government crackdown.
A violent campaign season
Wine, the frontrunner among 10 opposition candidates, has been arrested on numerous occasions since becoming an MP in 2017.
His supporters and campaign staff have also been taken into custody.
The government claims it has been stopping illegal gatherings to stop the spread of COVID-19. The opposition has said the bans on rallies in some parts of Uganda are a smokescreen for repression.
In November, was detained for allegedly violating regulations on campaigning aimed at preventing the spread of the coronavirus.
At least 54 people were killed across the country as security forces put down riots provoked by Wine's arrest.
"If you try to disturb peace, you will have yourself to blame. The security forces, following the law, are ready to deal with any troublemaker," Museveni warned this week.
Fears of an unfair poll
Ugandan elections are often marred by allegations of fraud and alleged abuses by the security forces. The European Union and the United Nations both warned Ugandan security forces not to use excessive force.
The African Union and East African bloc deployed election observer missions in Uganda. However, the EU said an offer to deploy a small team of election observers was "not taken up."
"The role of local observers will be even more important than before," the EU's foreign affairs chief Josep Borrell said in a statement.
Uganda's communications regulator on Wednesday ordered an internet blackout that also blocked access to social media and messaging apps.
The country has never witnessed a peaceful handover of power since its independence from Britain in 1962.