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 agreement marks the first direct commitment from both sides since rebels seized key cities in eastern Congo.

Congo and Rwanda-backed rebels on Saturday signed a declaration of principles in Qatar to end decades-long fighting in eastern Congo that commits them to a permanent ceasefire and a comprehensive peace agreement to be signed in one month.