Burundi on Tuesday vowed a thorough investigation into a series of deadly "terrorist" grenade blasts that hit the economic capital Bujumbura.
The attacks late on Monday followed a deadly grenade explosion in a bar in the capital Gitega on Sunday and a series of mortar shells fired on Burundi's international airport on Saturday night.
The interior ministry said in a statement that two people were killed when "still unidentified terrorists" hurled grenades in a Bujumbura parking lot and near a market on Monday night.
Medical and security sources told AFP that three people had died, while Prime Minister Alain-Guillaume Bunyoni said more than 100 had been injured.
The ministry said it condemned the "barbarity" of the blasts and pledged a "thorough investigation to put these nameless terrorist cowards out of action".
There were no claims of responsibility for the grenade attacks in Bujumbura or at the Gitega bar on Sunday which left two people dead.
They came on the heels of a mortar attack on Bujumbura airport on Saturday, which was claimed by the RED-Tabara rebel group in a statement on Twitter.
No one was injured in that assault, launched a day before President Evariste Ndayishimiye flew out for the UN General Assembly in New York.
"These are coordinated attacks launched by enemies of peace who have wanted to show for three days that there is no peace in Burundi when President Ndayishimiye is at the UN General Assembly," a senior Burundian official said on condition of anonymity.
"But they are mistaken. The situation is under control despite their little outbursts."
RED-Tabara, which has a rear base in South Kivu in the neighbouring Democratic Republic of Congo, emerged 10 years ago and is now the most active of Burundi's rebel groups.
It is accused of being behind many deadly attacks or ambushes across the East African country since 2015.
In 2020, it said it was behind a series of attacks that killed more than 40 people from the security forces and the youth league of the ruling CNDD-FDD party.
The Burundian government and many diplomats believed at the time that the rebel group, made up of an estimated 500-800 men, was led by one of the fiercest opponents of the state, Alexis Sinduhije, who has always denied the claims.