Four civilians and a soldier were killed and three others were wounded in the shooting late on Thursday.
“A group of four armed criminals wearing long coats entered … they started shooting at customers,” police spokesman Moise Nkurunziza said.
Hundreds have been killed and a quarter of a million people have fled Burundi since President Pierre Nkurunziza’s controversial decision last April to run for a third term, a vote he won amid opposition boycotts in July.
The latest efforts to hold talks between rival factions are due to open on Monday in the Tanzanian town of Arusha.
