A security advisor to Burundi’s vice-president has been killed in an attack by heavily armed men while dropping off his daughter at school.
General Athanase Kararuza and his wife died instantly. No-one has said they are behind the attack.
More than 400 people have been killed in the turmoil since President Pierre Nkurunziza said he would run for a third term last April.
A string of high-ranking army officials have been targeted during the conflict.
A general in charge of the president’s personal security Gen Adolphe Nshimirimana was killed in August, reportedly with machine guns and rocket launchers.
On Sunday the Minister for Human Rights Martin Nivyabandi survived being attacked with grenades as he was coming out of church.
BBC Great Lakes reporter Robert Misigaro says the killing is a blow for President Nkurunziza because it shows that he cannot guarantee the safety of his officers.
Timeline: Chaos in Burundi
- April 2015: Protests erupt after President Pierre Nkurunziza announces he will seek a third term in office
- May 2015: Constitutional court backs Mr Nkurunziza’s bid. Tens of thousands flee as demonstrations continue
- May 2015: Army officers launch a coup attempt, which fails
- July 2015: Elections are held, with Mr Nkurunziza re-elected. The polls are disputed, with opposition leader Agathon Rwasa describing them as “a joke”
- December 2015: 87 people killed on one day as soldiers respond to an attack on military sites in Bujumbura
- January 2016: Allegations emerge of mass graves and gang-rapes by Burundian security forces
- April 2016: The UN approves a resolution paving the way for a UN police force to be deployed in Burundi