Heavily armed attackers have launched co-ordinated assaults on several army barracks in Burundi.
An army spokesman said in a statement that 12 insurgents had been killed and another 20 arrested.
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.
UN officials have recently accused both government and opposition figures of stirring up ethnic tension between Hutus and Tutsis, amid fears of a return to genocide.
Earlier reports had said up to five soldiers had been killed, but an army spokesman now says five soldiers were wounded in the attacks.
Resident of the capital, Bujumbura, have taken cover at home and are too frightened to go to work or send their children to school, reports the BBC’s Prime Ndikumagenge from the city.
The attacks are the first on military targets since the coup attempt, he says.
