Earlier in the day, Bobi Wine said he was under house arrest after security forces prevented him from leaving his home.
The police said they had "taken some measures to stop [him] from instigating some people to hold unlawful assemblies and political demonstrations"

a government spokesperson said the planned protest was "simply a publicity stunt to disrupt the on-going meetings which constitutes breaches of public order and peace bordering on criminality".

But Bobi Wine told the BBC that holding protests was a constitutional right.

He wanted to use the fact that delegates from more than 100 countries are in Kampala for the Nam meeting, to highlight the opposition's issues with the government. Heads of state are due to arrive on Friday.

"We targeted the conference because [Nam] was established to fight for oppressed people of the global South. It was involved actively in the fight against apartheid.

"We want to send a strong message to the Non-Aligned Movement and remind them that the movement is losing its soul."

The opposition leader, who has been under arrest several times, has frequently complained of police harassment.

President Yoweri Museveni has been in power since 1986.

Nam was originally set up in 1961 - during the Cold War - to represent countries that were neither allied to the US nor the USSR. It has since developed into an organisation that tries to give voice to the concerns of the global South.