The chairperson of the AU commission, Moussa Faki Mahamat, said he paid tribute to the Burundian peacekeepers who lost their lives, but did not say how many died.
Only three countries have not yet started vaccinating at all against the coronavirus -- Burundi, Eritrea and North Korea.
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.
Witnesses said at least two grenades exploded in a bus parking area, causing panic.
Burundi has registered only 6,715 cases and nine deaths, according to the World Health Organization.
His predecessor, the late Pierre Nkurunziza, only left Burundi once during his last term in office when he went by road to neighbouring Tanzania.
A dozen people were also injured, according to this medical source and witnesses.
Linking Burundi with Tanzania’s Dar es Salaam port could be a boon for the mining industry in the nickel-rich nation.
The UK said it was adding the countries to its coronavirus travel ban list because of worries over the spread of a more contagious and potentially vaccine-resistant COVID-19 variant first identified in South Africa.
Ndayishimiye said the suspects can be handed over directly and there’s no need for mediators, his spokesman said in the statement.
The UN sought to extend the envoy's mission by a year despite a positive change on the part of new President Evariste Ndayishimiye.
Buyoya is at present the African Union’s High Representative for Mali and the Sahel.
After crossing the border with Burundi in Nyungwe Forest, the fighters were ambushed by RDF at 10 a.m. local time (0900 GMT), immediately arrested.
The country's senate has put together a panel of experts to assess the damage done during colonialism and advise on the cost of damages.
Eight other children were wounded in the blast on Thursday morning in the residential area of Gahahe on the outskirts of Bujumbura, a police spokesperson said.
Officially the country has reported only 170 cases and one death in two months.