One person died and five others were injured when police fired teargas and live bullets to disperse a demonstration. The protesters were angry at the alleged torture of detained lawmakers, including pop star Bobi Wine.
Ugandan police said on Sunday one person was killed in riots over the arrests of opposition lawmakers near capital Kampala.
Five other protesters were injured when police fired teargas and live bullets to disperse protesters who had barricaded a road in Mityana, about 60 kilometers (37 miles) from Kampala.
The demonstration was called to protest against the arrests and alleged torture of several popular opposition politicians including local pop star Robert Kyagulanyi — better known by his stage name Bobi Wine.
"One policeman fired bullets in a moving taxi (minibus) with passengers, injuring six people. Unfortunately one of them died," police spokesman Emilian Kayima told local media outlet NTV Uganda.
"We are looking for the policeman who committed this act, which is very irresponsible. He will be arrested and will be subjected to due process," he said.
Kyagulanyi and four other lawmakers were among dozens detained earlier this month in response to the stoning of a motorcade carrying the veteran president, Yoweri Museveni.
Some of the lawmakers were allegedly badly beaten in jail.
Bobi Wine and fellow lawmaker Francis Zaake are in "very bad condition" after being tortured, their lawyer Meldad Ssegona told Germany's DPA news agency on Sunday.
"Parts of Bobi Wine's body are swollen. He cannot speak properly. Worse, one of his kidneys has been damaged," the lawyer said.
Zaake "is still in coma and on life-support equipment. He is in a very critical condition," he added.
The lawmakers are charged with treason and illegal possession of weapons.
The crackdown on opposition lawmakers and the Ugandan media have raised fears that the Museveni-ruled country may be slowly sinking into anarchy.
ap/rc (Reuters, AP, dpa)