Numbers: About 5,000 members as of 2015, according to Libyan intelligence and U.S. officials

In Libya, Islamic State took root amid the political turmoil in the North African nation since the 2011 overthrow of dictator Moammar Gadhafi. Since late 2014, three armed Islamist groups have claimed allegiance to Islamic State leader Abu Bakr al-Baghdadi: Tripoli Province, Barqa Province, and Fezzan Province.

The three groups are believed to be tied to a central command. The factions have fighters in major Libyan cities. Over time, Tripoli Province has become dominant among the three groups.

In Dec. 2016 it lost control of the Mediterranean coast city of Sirte, Gadhafi’s birthplace—significantly, the only city outside Syria and Iraq that had been controlled by a group related to Islamic State. The U.S. has targeted and killed Islamic State figures in territory controlled by Tripoli Province.

According to Libyan intelligence and western diplomats a large, unknown number of Islamic State fighters also fled Sirte to the desert south of the city. On Jan. 19, the U.S targeted an Islamic State position there.