U.S. military forces have carried out a second strike against members of ISIS-K in Afghanistan, following the Thursday attack at the Hamid Karzai International Airport in Kabul that killed more than 200 people, including 13 U.S. service members.

A military official confirmed the strike to NPR on Sunday, saying it was conducted to eliminate an “imminent threat” to the airport. President Biden had warned Saturday of continued danger to U.S. operations in Afghanistan as evacuations there continue.

“U.S. military forces conducted a self-defense unmanned over-the-horizon airstrike today on a vehicle in Kabul, eliminating an imminent ISIS-K threat to [Hamid] Karzai International airport,” said Capt. Bill Urban, a spokesman for U.S. Central Command.”

“We are confident we successfully hit the target. Significant secondary explosions from the vehicle indicated the presence of a substantial amount of explosive material,” according to Urban. “We are assessing the possibilities of civilian casualties, though we have no indications at this time. We remain vigilant for potential future threats.”

On Friday, the U.S. conducted a drone strike in the Nangarhar province of Afghanistan. Pentagon officials said Saturday that “a planner and a facilitator” of ISIS-K were killed in that strike, with one other person injured.

The latest strike comes as President Biden and the first lady traveled Sunday to Dover, Del., where a “dignified transfer” of the remains of the 13 service members killed in Kabul last week will occur. Biden was also scheduled to meet with the families of the service members who were killed.