KINSHASA (AFP) - As the Democratic Republic of Congo struggles to stem unrest in its east, another newly formed armed rebel coalition has announced it is seeking to topple President Joseph Kabila's regime.

The Union of Revolutionary Forces of Congo (UFRC) is based in Bukavu, the capital of South Kivu province.

In a letter to United Nations Secretary General Ban Ki-moon on January 25 that was made public on Sunday, UFRC said it was a "political-military" movement founded in mid-January to bring down Kabila, who was reelected in November 2011 in contested elections.

The group, which claims to have the support of civil society members and political figures from South Kivu and "part of North Kivu", said it wants justice "for high treason" by Kabila.

DR Congo is already trying to contain rebels from the Movement of March 23 (M23) that have been fighting the army since May in neighbouring North Kivu province.

Hopes for a peace deal brokered by the UN and regional leaders failed on January 28.

Like UFRC, the M23 rebels want Kabila, who they accuse of reneging on a 2009 peace deal, to step down.

In a report last year, the UN accused the rebels of committing serious atrocities such as rape and murder and also accused Rwanda and Uganda of backing the M23 insurgents -- an accusation which both nations deny.

The new rebel coalition said it wants the UN to help it organise "democratic elections and rapidly reinstate political order capable of reducing the misery of Congolese people, and build the foundations of a real republic with proper participatory democracy."

It also rejected a UN proposal on January 25 to set up a 2,000-strong force in DR Congo to bolster its peace enforcement mission already present in the country.