Two US troops have been killed in a rocket attack on the main US base in Afghanistan, officials say.
Six other people, including two civilians, were injured in the attack on Bagram air base, a US military spokeswoman said.
Attacks on the base, situated 40 miles (60km) north-east of Kabul, are unusual, correspondents say.
The deaths bring the number of US military personnel killed in Afghanistan this year to at least 80.
Nato said in a statement that the troops belonged to its International Security Assistance Force (Isaf).
Isaf includes soldiers from more than 40 countries, including the US and a number of European states.
The US is sending 21,000 extra troops to Afghanistan this year, boosting the total foreign force in the country to some 68,000 Americans and 33,000 Nato-led forces.
In February 2007 a suicide bombing outside the Bagram base during a visit by then US Vice-President Dick Cheney killed more than 20 people.
I'm only posting this because I'm currently stationed on Bagram and was there last night when the mortars hit. It was really frightning but thankfully everyone I work with was not harmed. The mood on the base today is very somber especially since the attacks happened when we were supposed to be having a fallen commrade ceremony for three of our guys that were killed the other day off base.