According to the Burundian presidency, a former security chief who was a close ally of President Pierre Nkurunziza was shot dead on Sunday by gunmen wearing military uniforms, that heightened tensions after a disputed presidential poll.
General Adolphe Nshimirimana, who was in charge of the president's personal security at the time of his death, was shot dead in the Kamenge district of the capital Bujumbura. Nshimirimana was gunned down in a car alongside three of his bodyguards, sources said.
The four attackers wore military fatigues and sprayed the car with bullets, then drove off shortly after 8 a.m. local time (0600 GMT), witnesses told Reuters.
"Two had machine guns and two others rocket launchers. They came in military lorry and returned back in the same car," Paul, a taxi driver who witnessed the incident said.
Photos posted on social media showed a black bullet-riddled SUV with its front tyres flattened and side windows shot out.
"He has been killed by a bullet ... He was in the car with some bodyguards but I don't know exactly what happened," presidential adviser Willy Nyamitwe also said.
The army and police were unavailable for comment, according to Reuters.
The constitution states that the presidential elections should be held at least a month before the end of the president’s term on August 26.
Burundi has been hit by weeks of civil unrest as the country’s opposition wants President Pierre Nkurunziza to withdraw his third-term presidential bid, which is widely considered as violating the country's constitution, and the Arusha Accords, a 2005 peace deal that ended a civil war that lasted over a decade.
More than 70 people have been killed and 500 wounded since April, during protests opposing Nkurunziza’s decision to run for a third term.
More than 100,000 people have fled Burundi since the start of the crisis in April, according to the UN.
Burundi’s constitution limits the presidency to two terms in office, but Nkurunziza's supporters say he can run again because he was elected to his first term by lawmakers rather than the public.
Despite the country’s opposition vowing to boycott the polls and the US withdrawing its assistance, Burundi’s parliamentary elections proceeded on time, taking place on June 29.