ISIS-K: What to know about Taliban rival seen as threat to Afghanistan evacuation

What is ISIS-K?
The group referred to as ISIS-K is the "Khorasan" branch of the Islamic State, located in Afghanistan. Khorasan is a historic name for the broader region.

The insurgent group formed after a faction within the Taliban splintered and pledged allegiance to Abu Bakr al-Baghdadi – the leader of the Islamic State in Iraq and Syria – in October 2014.

By 2015 the offshoot ISIS-K became formally recognized as a terrorist organization, Katherine Zimmerman, a fellow in foreign and defense policy for the American Enterprise Institute, told Fox News.