Volkswacht Bodensee - Police clashes mar rally for Uganda opposition leader Bobi Wine

Ugandan President Yoweri Museveni, 81, who has ruled for four decades, also saw his candidacy for January's election approved by the electoral commission.

Hundreds of young people carrying portraits of Wine gathered on a Kampala street, defying the electoral commission's advice to avoid political gatherings because of security concerns.

Police used batons as some demonstrators tried to break through a cordon.

A youth leader from Wine's National Unity Platform, Allan Sewanyana, was among about a dozen people arrested, according to the party's secretary general Lewis Lubongoya.

Wine, a 43-year-old former singer whose real name is Robert Kyagulanyi, has emerged as Museveni's main opponent.

"Uganda has been ruled by one man with a small group of his family members for the last four decades, they have looted our country and this is the time he should hand over power," Wine said after his nomination.

"We know Museveni is scared of young people and would resort to brutal force to remain in power. I call upon all Ugandans and stand up and challenge dictator Museveni."

He has been arrested numerous times, with Museveni's son and heir-apparent General Muhoozi Kainerugaba repeatedly threatening on social media to behead him.

Last year, Kizza Besigye, another longtime Museveni opponent, was abducted from Kenya and brought to Uganda, where he now faces a possible death penalty in a treason trial.

D.Schlegel--VB