It is chaotic scenes in Kasangati after police blocked a campaign rally by candidate Robert Kyagulanyi, best known as Bobi Wine, and took him into custody.
It was not immediately clear why he was arrested.
But what is certainly clear is that his supporters are angry and are demanding his immediate release.
They were seen chanting slogans of support for their candidate, who is contesting in the Kyadondo East by-election alongside four other candidates, and wanted him to be set free.
Some were seen hurling stones at the security operatives.
Bobi Wine’s campaign manager Samuel Walter Lubega, a former presidential candidate himself, told reporters that he had been denied access to him.
“What kind of preventive arrest are police talking about when Bobi Wine was about to address his supporters?” he is quoted to have furiously said.
The contestants are in the evening of the campaign period ahead of Thursday’s election.