Burundi President Pierre Nkurunziza's top advisor escaped an assassination attempt Monday night, officials said.

Willy Nyamitwe, the president's communication advisor was ambushed by armed men on his way home.

One of his bodyguards was killed and another wounded while he sustained injuries on the arm.

Police said the attackers were waiting in a nearby house under construction before launching the ambush.

"Thank God, Willy Nyamitwe narrowly escaped an attack...," tweeted Burundi's UN ambassador Albert Shingiro.

Nyamitwe is one of the most public voices emerging from Burundi, an active tweeter who frequently criticises the West for interfering in the country.

"I thank those who wish me a speedy recovery. I am doing well but saddened by the death of a best friend, the policeman Gasongo," Nyamitwe tweeted after the attack.

His brother Alain Aime Nyamitwe, also Burundi's foreign minister, described the assassination bid as "a new, pointless effort to disturb republican institutions".

Burundi has been in turmoil since President Pierre Nkurunziza announced plans in April last year to run for a third term, which he went on to win.

More than 500 people have been killed and at least 300,000 have fled the country, while several well-known figures, including high-ranking military officers, have been assassinated.

A volley of reports by international rights groups accusing the government of atrocities and warning of genocide has infuriated Bujumbura, which says there is a "foreign plot" to overthrow the government.