Bagram, Parwan province: Three American service members and a US contractor were killed when their convoy hit a roadside bomb on Monday near the main US base in Afghanistan, the US forces said.
The Taliban has claimed responsibility for the attack.
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 base in Bagram district is located in northern Parwan province and serves as the main US air facility in the country.
The wounded were evacuated and are receiving medical care, the US forces' statement said.
It added that in accordance with US Department of Defence policy, the names of service members killed in action were being withheld until after the notification of next of kin.
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.
The conflicting accounts could not be immediately reconciled.
Also Read: Gunfire at anti-government protest in Sudan
The fatalities, which bring to seven the number of US soldiers killed so far this year in Afghanistan, underscore the difficulties in bringing peace to the war-wrecked country even as Washington has stepped up efforts to find a way to end the 17-year war, America's longest.
