The United States has launched a drone strike against ISIS-K, a faction of the Islamic State that claimed responsibility for the deadly bombing at the Kabul airport earlier this week.

“U.S. military forces conducted an over-the-horizon counterterrorism operation today against an ISIS-K planner,” Capt. Bill Urban, a spokesman for U.S. Central Command, in a statement to NBC News. “The unmanned airstrike occurred in the Nangarhar Province of Afghanistan. Initial indications are that we killed the target. We know of no civilian casualties.”

The attack comes just hours after President Joe Biden vowed retaliation over Thursday’s suicide bombing, that left more than a hundred people dead, including at 13 US service members.

“To those who carried out this attack, as well as anyone who wishes America harm, know this: We will not forgive. We will not forget. We will hunt you down and make you pay,” Biden said on Thursday.

Per a report by The New York Times, the U.S. Embassy in Kabul again warned citizens at certain gates (Abbey gate, East gate, North gate or the New Ministry of Interior gate) at the Kabul airport to “leave immediately,” citing security threats. The alert advised U.S. citizens “to avoid traveling to the airport and to avoid airport gates.”