Heavily armed attackers have launched co-ordinated assaults on several army barracks in Burundi.
At least seven people, including some attackers, have reportedly been killed in Bujumbura, the capital.
Witnesses described hearing gunfire and explosions for several hours, in Musaga in the south and Ngagara in the north.
The incident is the worst violence since an attempted coup in May, sparked by President Pierre Nkurunziza’s third-term bid.
Bujumbura residents have taken cover at home and are too frightened to go to work or send their children to school, reports the BBC’s Prime Ndikumagenga from the city.
The attacks are the first on military targets since the coup attempt, he says.
A presidential adviser said that government opponents had been trying to create a diversion to free prisoners with the attacks, but had failed.
Mr Nkurunziza won a disputed election in July.