New Delhi, July 21 -- Congo and Rwanda-backed rebels have signed a declaration of principles for a permanent ceasefire in eastern Congo, where ethnic tensions and quest for rich minerals have resulted in one of Africa's longest conflicts with thousands killed this year.

The African Union called Saturday's signing, facilitated by Qatar, a "major milestone" in peace efforts. Qatari authorities said it paves the way for "a comprehensive peace that addresses the deep-rooted causes of the conflict" in the Central African nation.

The conflict dates back to the Rwandan genocide

The conflict can be traced to the aftermath of the Rwandan genocide of 1994, when Hutu soldiers and militias killed between 500,000 and 1 million minority Tutsis as we...