KAMPALA, Uganda (AP) — Ugandan police have detained the singer and political activist known as Bobi Wine, who planned Monday to hold his first public meeting with supporters as a presidential aspirant.

Police fired tear gas as they dispersed the crowd outside the capital, Kampala. Gunfire was heard but it was not clear if live rounds or rubber bullets were fired.

The foiled meeting had been authorized by electoral authorities. It was the first of several planned by Wine, whose real name is Kyagulanyi Ssentamu.

A police spokesman did not immediately respond to questions.

Police have repeatedly prevented the opposition lawmaker from addressing rallies or even organizing musical concerts in recent months, saying the events pose a danger to the public.

Presidential election is set for 2021.

The singer and activist has called for the retirement of longtime President Yoweri Museveni, saying young people must prepare to take over leadership of the East African nation. Museveni, who has indicated he will run again, accuses him of trying to lure his supporters into rioting.