A U.S. military drone strike on a car with explosives that was reportedly about to target the Kabul Airport reportedly killed 10 Afghan civilians on Sunday.

Some of the people were in the car and others in adjacent rooms in a house. Those killed include seven children, an aid worker for an American charity organization, and a contractor with the U.S. military, The New York Times reported.

When Zemari Ahmadi, who worked for the Nutrition and Education International charity organization, drove into the street where he lived, he was greeted by his children, some of whom entered his car. At that time, a drone struck the rear end of his Corolla, blowing out doors, shattering windows and spraying shrapnel. Mr. Ahmadi and some of the children were killed inside his car, while others were fatally wounded in adjacent rooms, family members said.

An Afghan official confirmed that three of the dead children were transferred by ambulance from the home on Sunday.

Ahmadi’s daughter Samia, 21, was inside when she was struck by the blast, reported The New York Times.

“At first I thought it was the Taliban,” she said. “But the Americans themselves did it.”

A spokesman for the U.S. Central Command said on Sunday that the U.S. military had carried out a drone strike against an ISIS-K vehicle planning to attack Hamid Karzai International Airport. The group had claimed responsibility for the suicide bombing at the airport that killed 13 Americans and dozens of Afghanis. 

On Monday, Capt. Bill Urban, the spokesman, reaffirmed an earlier statement that the military hit a valid target, an explosives-laden vehicle. He also repeated that the military was investigating claims of civilian casualties.

It is unclear what connection there is between Ahmadi and ISIS-K. According to relatives and neighbors, there is no connection, and Ahmdadi was a charity worker.

A Taliban spokesman Zabihullah Mujahid told China’s state television CGTN on Monday that seven people were killed in the drone attack, and described the U.S. action on foreign soil as unlawful, Reuters reported.

“If there was any potential threat in Afghanistan, it should have been reported to us, not an arbitrary attack that has resulted in civilian casualties,” Mujahid said in a written response to CGTN.

ISIS-K is an enemy of the Taliban and the United States. This is the second drone attack the U.S. has completed since the suicide bombing at the airport.