The U.S. military is increasing its airborne surveillance of Mexican drug cartels to collect intelligence to determine how to best counter their activities, the top U.S. general overseeing troops in North America said on Thursday.

Security forces in Mexico have arrested a pilot they suspect of working for Los Chapitos, the Mexican cartel run by sons of the jailed drug lord Joaquín '"El Chapo" Guzmán. The pilot, known by the alias of "El Jando", was detained in the northern city of Culiacán, the stronghold of Los Chapitos, in an operation in which one soldier was shot dead.

"The cartels have increased and actually escalated their threats and are actually using drones to drop explosives on rival cartel members or even the military."