DAKAR, Senegal — The Democratic Republic of Congo and Rwanda-backed rebels have signed a declaration of principles for a permanent ceasefire in eastern Congo, where ethnic tensions and a quest for rich minerals have resulted in one of Africa’s longest conflicts, with thousands killed this year alone.

The Democratic Republic of the Congo (DRC) and the M23 rebel group have signed a declaration of principles in Qatar to end fighting in eastern Congo. The declaration was signed on Saturday between representatives of both sides in Doha.