Top US officials are expressing concerns that ISIS is putting efforts in to organizing its Libyan allies, and are making serious inroads in the nation.
In October, an Islamist faction in Derna pledged loyalty to ISIS, and began calling itself ISIS, which allowed it to attract a large number of new recruits, and expand into several other cities.
The extent of the relationship between ISIS and its affiliate has been a matter of a lot of speculation, but US officials say several ISIS leaders are known to have traveled to Libya to advise this affiliate and help them organize.
The State Department also raised its estimate of the number of ISIS fighters in Libya, saying they believe the faction has between 1,000 and 3,000 fighters there. This may be an underestimation, as neighboring Tunisia alone estimates some 4,000 of their citizens are fighting for the Islamists in Libya.