On Wednesday, Maj. Gen. Godefroid Niyombare said he had dismissed the Burundian government over President Nkurunziza's disputed bid to run for a third term.
The general, who was fired as the country's top intelligence official in February, said he had established a national concord committee to govern the country.
The president's office responded by saying that the situation was "under control" and that the coup attempt had failed.
Widespread protests erupted in Burundi in late April following Nkurunziza's announcement of a new reelection campaign, which opponents say contradicts the country's constitution.
Nkurunziza, 51, has served as the president of the country in Southeast Africa over the past decade after being first elected unopposed by members of parliament in 2005.