At least four people were injured after two grenades exploded outside the army hospital in the capital, part of a wave of violence appearing to target the military, a Burundian official said Thursday.
Authorities do not know who carried out the attack, which follows the killings of two senior army officers on Tuesday, military spokesman Col. Gaspard Baratuza said.
One of the victims of the gun attacks on Tuesday was a lieutenant colonel in charge of security operations in the parts of the capital of Bujumbura seen as opposition strongholds.
Burundi has been hit by unrest since April 2015 when President Pierre Nkurunziza announced his decision to seek a third term, which he eventually won.
Carina Tertsakian, who researches Burundi for Human Rights Watch, said that while it is not clear who is responsible for the attacks on the army officers, “the existing divisions in the army appear to be deepening, leading to increasing tensions, suspicion and fear.”
There is concern the killings could trigger reprisal attacks.
“We’ve seen in the past that attacks like this on military or police often lead the security forces to arbitrarily arrest or even kill people who have nothing to do with the attacks,” she said.
The U.N. estimated in January that at least 439 people have been killed, but many more have died since.
Human rights groups blame Burundi’s security forces for most of the killings, although a new rebel group has been formed and there have been attacks on government officials.