One of Haiti's most powerful gang leaders has written the U.N. Secretary General and requested that the organization deploy a delegation to Haiti for dialogue and mediation amid fears that Salvadoran troops deployed after the disappearance of aviation technicians from that country could escalate violence.

Wilson Joseph, best known as Lanm Sanjou and leader of the 400 Mawozo gang, sent the letter on Monday, and the U.N. has received it, a source who wasn't authorized to discuss the situation confirmed.

The letter calls 400 Mawozo a "rebel group" and was sent from Plaine du Cul-de-Sac, where a group of four Salvadoran aviation technicians were attacked on Oct. 18 and remain missing.