The general in charge of keeping Burundi's president safe has been assassinated by gunmen wielding rocket launchers and wearing military uniform.

General Adolphe Nshimirimana was killed in a car alongside three of his own bodyguards when the four attackers opened fire at about 8am local time on Sunday.

Pictures on social media show a black bullet-riddled SUV with its front tyres flattened and side windows shot out.

General Adolphe Nsshimirimana was killed in a car alongside three of his own bodyguards

General was a close ally of controversial President Pierre Nkurunziza (pictured on a bike), who stood for a third term despite the fact it was against the country's constitution

Witness Paul, a taxi driver, said: 'Two had machine guns and two others rocket launchers. They came in military lorry and returned back in the same car.'

The general's death is the latest incident of violence in a country which has descended into chaos since April, when President Pierre Nkurunziza announced he was standing for a third term - a move which violated the constitution.

The constitution was agreed in a peace deal that ended an ethnically-charged civil war in 2005, and the announcement it would be ignored by Nkurunziza was followed by protests and a coup attempt.

Some of the army generals behind the attempted coup have vowed to lead a rebellion to oust Nkurunziza, who won the July 21 presidential poll with almost 70 per cent after the opposition boycotted the elections.

Some of the army generals behind the attempted coup have vowed to lead a rebellion to oust Nkurunziza, who won the July 21 presidential poll with almost 70 per cent after the opposition boycotted the elections. Pictured: Police patrol after the killing in Burundi's capital Bujumbura

Nsshimirimana was one of the president's close allies, and was in charge of his personal security.

'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 told Reuters.