Authorities in Mexico say they have arrested a close associate of one of the country's most powerful drug traffickers.

Manuel Fernandez Vellencia is alleged to be a main collaborator of notorious drug trafficker El Chapo Guzman. Fernandez was arrested Sunday during a police operation in northern Mexico after a shootout. Police said they had been looking for Fernandez for a long time. Guzman is the head of powerful Sinaloa cartel and considered one of the main players in a bloody turf war that exploded in 2005.