The east African country was rattled by widespread opposition led anti-government protests in April and May, sparked by rising consumer prices, and Besigye was arrested and charged in court and beaten severely by security agents.
Besigye’s rally was part of a candle light memorial service near the home of a 6-year-old girl who was shot and killed during one of the violent protests, dubbed “walk to work”.
Police fired tear gas canisters at a procession of opposition supporters, dispersing opposition supporters and mourners who were making their way through Masaka town to her graveside to lay flowers.
A police officer grabbed a wreath of flowers that was intended to be laid at the graveside and ripped it apart.
The previous protests provoked a government crackdown in which nine people were killed and hundreds of others injured, according to Human Rights Watch, which also accused the police of using excessive force against unarmed civilians.
“Walk to work starts today again and we are starting by mourning the victims of police brutality in April and May,” Besigye told the rally.
“So when you hear our call to come and walk you should all rise up in huge numbers and we take over the whole of Kampala.”
Police were not immediately available to comment.