The UN has evidence that rebels in the Democratic Republic of Congo are being supported and trained by Rwanda, according to a report in the British media.
A BBC journalist said he has seen an internal UN report stating some of the rebel leaders are Tutsi officers, the second largest ethnic group in Rwanda, and that they have links to Kigali.
However, Rwanda’s foreign minister denied the country has any involvement.
The conflict broke out in April following a mutiny by former rebel leader Bosco Ntaganda and around 600 followers.
Though integrated into the DRC’s army, Ntaganda is wanted by the International Criminal Court (ICC) for war crimes and was going to be arrested.
There have been reports of rival armed groups in the east of the country killing civilians, as they target each other’s families.
The UN’s local peacekeeping mission MONUSCO has deployed helicopters in an effort to stop the civilian deaths.
Around 100,000 people have fled their homes since the violence began, with many seeking refuge in Rwanda and Uganda.