ISIS forces are making a new round of gains along the western Libyan coast, seizing more territory in Sirte and moving westward toward Misrata, the base of operations for the current Tripoli government.

Western officials are expressing alarm at the sudden shift, with officials from the Misrata militia insisting they had no choice but to retreat in the face of recent offensives by ISIS. Concern of falling morale among their forces is adding to fears that ISIS will be able to expand greatly in this area.

The Misrata militia, now known as Libya Dawn, was one of the major powers during the Libyan Civil War, and retained autonomy in the city after the ouster of Gadhafi. They’ve since expanded, and now control Tripoli and much of the rest of the country’s west, while the Western-backed government is operating out of Tobruk, near the Egypt border, and controls only a portion of the east. The rest of the country is mostly held by various militias, with ISIS taking much of the central coast.

ISIS in Libya was actually a totally separate Islamist militia faction which pledged loyalty to the Syria-based leadership last year. Since then, they’ve gained advisers and training from parent ISIS, and a much higher profile that has allowed them to recruit more easily.