Nairobi (AFP) - Burundi's rebels came together Wednesday for the first time as a force aimed at ousting President Pierre Nkurunziza, after months of deadly violence.

The rebels have called themselves the Republican Forces of Burundi, or "Forebu" from its name in French, Les Forces Republicaines du Burundi, said Edward Nshimirimana, a former army colonel turned rebel.

The rebels have formed a force "to protect the population" and uphold the Arusha Agreement that paved the way to the end of the 1993-2006 civil war but which they say Nkurunziza has violated by his third term in power.

"Our goal is to drive out Nkurunziza by force to restore the Arusha accord and democracy," Nshimirimana told AFP by telephone.

Nkurunziza, an ex-rebel and born-again Christian who believes he has divine backing to rule, won a third term in office in July.

A coup attempt in May was crushed after two days, with many of the soldiers and police who took part fleeing.

While there have been near daily gun battles in the capital, attacks are now taking place in other parts of the country too, but until now the force had no name.

The formation of Forebu is significant, as Bujumbura's government has dismissed talk of rebellion, instead rather blaming attacks on "armed criminals" or insurgents.

The United Nations has warned that the small central African country risks sliding back into civil war as violence continues.

The rebels condemned the "barbarity of Nkurunziza's regime" and said they were driven to rebellion in the face of violence from state security forces and the government's "categorical and arrogant rejection of any dialogue."

Burundi plunged into civil war on ethnic lines between majority Hutus and minority Tutsis in 1993, at a cost of an estimated 300,000 lives by the end of the conflict in 2006.

Attacks, which have included failed mortar attacks on the presidential palace, already echo those carried out during the civil war.

AFP