Burundi’s president Pierre Nkurunziza has condemned the killing of Brigadier General Athanase Kararuza who was shot dead on Monday by armed men in Bujumbura.
Nkurunziza has also ordered investigations to unmask those behind the attack.
The former military adviser to the vice president was dropping off his kids to school in a neighbourhood in Bujumbura before being ambushed by armed men.
His wife and bodyguard also lost their lives in the shootout.
The late senior military official was influential in the fight against coup plotters last year and contributed in maintaining a state of law.
Nkurunziza has faced tough resistance from his opponents ever since he decided to stay in power.
Opponents say Nkurunziza’s third term goes against the terms of a peace agreement which ended the civil war in Burundi.
According to UN officials, about 400 people have been killed and 250, 000 others have been displaced as a result of the crisis.