Southern and Eastern African countries have expanded a team of former heads of state overseeing efforts to resolve the conflict in eastern Congo, in an attempt to give fresh impetus to negotiations that have repeatedly floundered.

The latest setback came on Monday when the M23 rebels went back on a pledge to withdraw from the strategic town of Walikale and accused the army of failing to halt its own offensive operations there.

The conflict is rooted in the fallout from the 1994 genocide in Rwanda and competition for control of mineral riches. 

Since M23 stepped up its offensive in January, it has seized control of eastern Congo's two largest cities in fighting that has killed thousands and raised fears of a wider regional war.    

Following a virtual summit on Monday, the main Southern and Eastern Africa political blocs appointed five former heads of state to "facilitate" a peace process, they said in a statement.

The appointees are Nigeria's Olusegun Obasanjo, South Africa's Kgalema Motlanthe, Ethiopia's Sahle-Work Zewde, Kenya's Uhuru Kenyatta and Central African Republic's Catherine Samba Panza.

Congo's presidency said the new panel would name a mediator to replace Angolan President Joao Lourenco, who withdrew from the role on Monday following years of largely fruitless efforts to ease tensions between Rwanda and Congo.

Rwanda's government, which has been sanctioned by several Western countries for supporting M23 with arms and troops, said on X that leaders at the summit "committed to a political solution that addresses the security concerns of all parties."

Rwanda denies supporting M23 but also says its forces are acting in self defence against Congo's army and militias hostile to Kigali.

REGIONAL TENSIONS

Congo President Felix Tshisekedi and his Rwandan counterpart Paul Kagame held their first direct talks last week in Qatar, where they voiced support for an immediate ceasefire. M23 has dismissed those calls, saying the conflict can only be resolved through negotiations between the rebels and Kinshasa.

A meeting was scheduled last week in Angola after Tshisekedi dropped his longstanding refusal to negotiate with M23, but the rebels withdrew in protest at new European Union sanctions. 

The conflict has threatened to spiral into a wider conflagration, with the armies of Congo, Rwanda and Burundi all taking part in fighting.

President Evariste Ndayishimiye of Burundi, whose troops have fought in support of Congo's army against M23, warned in an interview with the BBC that Rwanda "has a plan to attack Burundi."

"Burundians will not accept to be killed as Congolese are being killed," he was quoted as saying in a report published on Tuesday, adding he wanted to resolve the problem through dialogue.

Burundi and Rwanda have long had tense relations, but officials from the two sides have met in recent weeks.

"These comments are surprising because Rwandan and Burundian defence and security institutions have actually been meeting to discuss how to secure our common borders," Rwanda's government spokesperson Yolande Makolo told Reuters.