Military officials in Afghanistan say a rocket attack on the main U.S. base outside Kabul killed two American soldiers early Sunday.
A U.S. military statement says six other Americans, including two civilians, were wounded in the attack on Bagram Air Base, 40 kilometers northeast of the capital.
Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack.
The two deaths bring to at least 80 the number of U.S. forces killed in Afghanistan this year.
In another incident overnight, NATO said three Afghan civilians were killed and about 17 others wounded in the Pech District of the eastern province of Kunar. Alliance officials say the civilians were between attacking insurgents and an Afghan National Army outpost.
U.S. President Barack Obama has ordered the deployment of 21,000 more troops and trainers to Afghanistan to fight the worsening Taliban insurgency and help with reconstruction.
Despite the arrival of more foreign troops, violence in the past year has risen to the highest levels since the U.S.-led invasion in late 2001.