The Pentagon has said it disrupted a new attack planned by the Islamic State extremist group through a Reaper drone strike on August 29 -- the day before US troops ended their 20-year mission and following a devastating attack outside the airport where vast crowds rushed to leave the victorious Taliban.

But Kabul resident Aimal Ahmadi earlier told AFP that the strike killed 10 civilians including his small daughter, nephews, nieces and his brother Ezmarai Ahmadi, who was driving the car that was struck after he parked.

The New York Times, analyzing security camera footage, said the US military may have been seeing the slain Ahmadi and a colleague loading canisters of water, which was in short supply after the collapse of the Western-backed government, and picking up a laptop for his boss.

Ezmarai Ahmadi was an electrical engineer for the California-based aid and lobbying group Nutrition and Education International and himself was among thousands of Afghans who had applied for resettlement in the United States, relatives said.

US officials say that a larger blast took place after the drone strike, showing that there were explosives in the vehicle.

But the New York Times investigation said there was no evidence of a second explosion, with only one dent on a nearby gate and no clear signs of an additional blast such as blown-out walls.

Aimal Ahmadi earlier told AFP that 10 civilians were killed. US officials have acknowledged three civilian deaths but argued that the hit prevented another deadly attack.

Commenting on the report, Pentagon spokesman John Kirby said that US Central Command "continues to assess" the strike but that "no other military works harder than we do to prevent civilian casualties."

"As Chairman (Mark) Milley said, the strike was based on good intelligence, and we still believe that it prevented an imminent threat to the airport and to our men and women that were still serving at the airport," Kirby said, referring to the top US general.

The New York Times noted that a rocket attack the following morning, claimed by the Islamic State group, was carried out from a Toyota Corolla similar to Ahmadi's.

More than 71,000 Afghan and Pakistani civilians have died directly from the war launched by the United States after the September 11, 2001 attacks, with casualties rising dramatically after then president Donald Trump relaxed rules of engagement in 2017, according to a Brown University study in April.