Police spokesman Fred Enanga confirmed Tuesday that one civilian was killed in the scuffles and that police fired tear gas and rubber bullets to disperse crowds.
Opposition leader Kizza Besigye, who is in a tight race with Ugandan President Yoweri Museveni, said Tuesday he does not believe the election, to be held Thursday, will be free and fair.
Besigye was blocked by police from addressing some rallies in Kampala Monday by police who said he had defied their orders to take less congested routes.