The Interior Ministry put the death toll at two and said on Twitter that “unidentified terrorists” were responsible.
Two grenade explosions hit a bus parking lot in the in Burundi’s largest city Bujumbura on Monday night, according to seven eyewitnesses, while a third blast hit Jabe market in the Bwiza neighbourhood, according to another witness.
Five people were killed and about 50 injured, a health worker helping to care for the injured told Reuters on Tuesday.
“I saw people running in all directions, some crawling to find cover,” said a witness to the second explosion at the bus parking lot.
During a visit to the wounded in hospital, Prime Minister Alain-Guillaume Bunyoni, told reporters the attacks had killed four and promised government help for those wounded.
On Sunday, a grenade attack in the administrative capital Gitega killed two, according to local media. It was not clear who was responsible.
An airport worker confirmed there had been an attack on the Bujumbura airport on Saturday. He declined to say what weapons were used and said the building had not been damaged.
Congo-based rebel group Red Tabara claimed responsibility for the airport attack in a statement on Twitter. It said it fired mortars as the president prepared to travel to the United Nations General Assembly in New York.
Burundi, a nation of about 11.5 million people, has suffered decades of war and ethnic and political bloodletting. The United Nations says the youth wing of the ruling party and the security services are complicit in the torture, gang-rape and murder of political opponents, charges the government denies.