There is a growing sense of panic among the residents of the Anbar Province city of Fallujah, a Sunni Arab city of some 300,000 people under ISIS control, as Iraqi Shi’ite militias approach the area, talking up a full-scale offensive to retake the city.

Fallujah is no stranger to sieges, the site of multiple bloody attacks by US forces during last decade’s occupation. Local council chief Eissa al-Issawi warns that the Shi’ite attack would cause “much destruction, and much blood” in a city that has already seen more than it’s share of that.

Locals say ISIS is preventing the mass exodus of civilians out of Fallujah, likely not wanting to have to absorb them as refugees into other cities deeper into their territory. Fleeing would be hard at any rate, as Anbar Province is just one big battleground dotted with intermittently besieged cities.

ISIS, for its part, is launching offensives against Iraqi forces near both Ramadi and Fallujah, trying to open up multiple fronts to prevent them from surrounding Fallujah. The easternmost major Anbar city, Fallujah is to be the first stop for the militias, but if they have it their way, it won’t be the last.