The Presidential Office quickly rubbished the declaration by Major General Godefroid Niyombare, who was fired by Nkurunziza as intelligence chief in February. "We consider it as a joke not as a military coup," presidential aide Willy Niyamitwe told reporters.

But crowds of people streamed onto the streets of Burundi's capital, cheering and singing, after the announcement and soldiers surrounded the state broadcaster building.

Niyombare made his declaration to reporters at a military barracks in Bujumbura, while the president was out of the country at an African summit on the crisis.

Niyombare, also a former ambassador to Kenya, was surrounded by several other senior officers in the army and police, including a former Defence Minister.

"Regarding President Nkurunziza's arrogance and defiance of the international community which advised him to respect the constitution and Arusha peace agreement, the committee for the establishment of the national concord decide President Nkurunziza is dismissed, his government is dismissed too," he claimed.

More than 20 people have been killed since street protests erupted in the impoverished central African state more than two weeks ago, according to an unofficial count by activists.

The demonstrators say Nkurunziza's bid for another five years in office violates a two-term limit in the constitution and the Arusha peace deal, which ended an ethnically fuelled civil war in 2005 that killed 300,000 people.

Latest News from World News Desk