The Forum for Democratic Change (FDC) Deputy Secretary General, Mr Harold Kaija, has been arrested by military police in Hoima District.
Mr Kaija was arrested on Thursday evening together with Ms Happy Nasasira, the Nakawa division councillor to KCCA, Mr Robert Runyangwe and one Nasur.
"We have been intercepted by military police on our way from Kibaire polling station. They ordered us to board their pick up. We don't know why we have been arrested," Ms Nasasira said.
They were driven to Hoima Central Police station from where they are currently recording statements.
The Albertine regional police spokesperson Mr Julius Hakiza confirmed the arrests, but declined to give details.
"They are being investigated over electoral offenses. We shall give you details," he said.
Vote counting is still ongoing with FDC's Asinansi Nyakato reportedly in an early lead. She is battling it out with NRM's Harriet Businge Mugenyi.
There is tension in the district as the electoral commission conducts tallying of votes at its office.
There is heavy military and police presence on the streets of Hoima town pending the announcement of the winner of the highly contested poll.
Each camp has started celebrations across the town, leaving many residents perplexed.