"A number of Afghan civilians were also killed and injured in the attack," General Kenneth McKenzie told reporters. "We're still working to calculate the total losses."

McKenzie also said the US airlift in Kabul will continue despite the attacks.

"Let me be clear. While we're saddened by the loss of life, both US and Afghan, we're continuing to execute the mission," he said, "which is to get as many evacuees and citizens out of Afghanistan."

McKenzie said he expected IS militants to attempt further attacks but that "will not deter us from accomplishing the mission."

The general said two suicide bombers had detonated explosives near the Abbey Gate at Kabul airport and the nearby Baron Hotel.

He said a number of IS gunmen then opened fire on civilians and military forces.

The US airlift is scheduled to end on August 31 with a complete withdrawal of US troops from Afghanistan.