The death toll from Thursday’s suicide bombing outside of the airport in Kabul continues to climb. At least 13 U.S. servicemembers were killed, while more than a dozen others were wounded. As of now, we still don’t know how many Afghans or others were killed. Current estimates say well more than 100 Afghans perished.

The Islamic State-Khorasan Province (often referred to as ISIS-K by the U.S. government) quickly claimed responsibility for the heinous attack. No one was surprised. In the days leading up to the bombing, American officials, including President Joe Biden, repeatedly warned that ISIS-K could strike at any time. 

And so it did. 

Here are answers to some of the basic questions that are being asked about ISIS-K.