Three US service members and an American contractor were killed when their convoy hit a roadside bomb on Monday near the main US base in Afghanistan, a statement by the US forces said.
The US and NATO Resolute Support mission said the four Americans were killed near the Bagram Air Base, north of Kabul, while three others were wounded in the explosion.
The Taliban claimed responsibility for the attack, according to the Associated Press (AP)
All wounded were evacuated and are receiving necessary medical care.
The names of service members killed in action were being withheld until after the notification of next of kin, the statement noted.
In their claim of responsibility, the Taliban said they launched the attack and that one of their suicide bombers detonated his explosives-laden vehicle near the NATO base.
Meanwhile, an Afghan official also said a Taliban attack on a joint army and police base in northern Sari Pul province killed at least five members of the country's security forces.
Zabihullah Amani, the provincial governor's spokesman, said the Monday night attack in Sangcharak district also wounded seven other troops, AP reported.
Taliban did not immediately comment.
Amani says four insurgents were also killed in the ensuing clashes.
