Burundi's defence minister has called for army unity after a failed coup against President Pierre Nkurunziza and demanded soldiers hiding "rejoin their units."

Defence Minister Emmanuel Ntahonvukiye, a civilian named on Monday after his predecessor was sacked, made the appeal alongside the army chief of staff Prime Niyongabo late Wednesday, according to a statement.

"The survival of Burundi as a nation depends on the cohesion of the army," the statement read, warning that should the military splinter, it would result in a situation as seen in war-torn Somalia.

Troops were also told "not to interfere in the management of political affairs, avoid any form of violence, and respect human rights and the principles of international humanitarian law."

One week after a coup led by a top general was crushed -- with soldiers fighting each other on the streets -- security forces this week have battled to end the anti-government protests against Nkurunziza's bid for a third term in power that have been raging in parts of the capital since late April.

More than 20 people have died in weeks of clashes with security forces that halted during the coup attempt, but the protests resumed this week.

The leader of coup attempt, General Godefroid Niyombare, has gone on the run after escaping capture, but 20 soldiers involved were arrested.

Some soldiers were "manipulated" into taking part, the statement added, calling for those in hiding to return to their units.

Burundi's 13-year civil war between the former Tutsi-dominated army and Hutu rebels -- made of up several sometimes competing factions -- ended in 2006, leaving some 300,000 dead.

As part of the Arusha Agreement in 2000, which paved the way for a final peace, the army and police were to be reformed with equal numbers of Tutsi and Hutu, in a country where Hutus make up some 85 percent of the population.

But the army statement said that the coup bid was "carried out by a group of mutineers and had no ethnic connotations."

In the days immediately after the coup bid, it was soldiers rather than police who were mainly deployed to end demonstrations and who are seen by many protesters as being more neutral. However, police were seen Wednesday returning to stem the protests.

Some accuse the police of backing the ruling party's Imbonerakure youth group, a powerful force described by the UN as a militia and accused of a string of abuses and killings.