Three people were killed in violent clashes between Ugandan security forces and protesters Wednesday, police said, after the latest arrest of presidential candidate Bobi Wine.
Thirty-four people were also injured in the capital Kampala as police used tear gas and "other lethal weapons" against protesters, police spokesman Fred Enanga told AFP.
The Uganda Red Cross said in a statement that it treated more than 30 people in Kampala following "scuffles involving the police and the rioting masses", including 11 people for gunshot wounds.
Kampala police commander Moses Kafeero said earlier Wednesday that Wine, a pop star-turned-MP who is President Yoweri Museveni's main opponent in the 2021 presidential election, had been arrested for violating coronavirus measures at his rallies.
It is the latest in a string of arrests of the singer, whose real name is Robert Kyagulanyi. He was still being held for questioning late Wednesday.
"Bobi Wine has continuously violated electoral guidelines on Covid-19, holding rallies, processions and hosting more than the recommended 200 people per campaign venue," Kafeero said.
"As law enforcement, we can't stand and watch as politicians put the lives of Ugandans at stake by encouraging processions and huge rallies, which fuel Covid-19 transmission."
The arrest sparked protests in Kampala and other major towns, where Wine's supporters lit fires in the middle of roads and lobbed rocks at police, and were dispersed with tear gas and rubber bullets.
Uganda's police chief Martin Okoth Ochola had warned that officers were taking "a tougher approach to preserve the integrity of the electoral process."
Wine was most recently arrested on November 3 moments after registering his candidacy for the January 14, 2021, presidential election, over accusations he was planning an illegal rally.
Wine, nicknamed the "Ghetto President", has faced escalating police harassment since announcing his intention to challenge Museveni, who seized power at the head of a rebel army in 1986.
His catchy pop songs about social justice, poverty and corruption have shaken the ruling party and its ageing patriarch Museveni, who at 76 is the only president most Ugandans have ever known.