The Afghan Taliban have claimed responsibility for an attack that killed four US troops on the same day that peace talks between America and the group were announced.
US defence officials had earlier said four US troops were killed at or near Bagram Air Base. Taliban spokesman Zabiullah Mujahid said the insurgents fired two rockets into the base.
Officials said the four were killed by indirect fire, likely a mortar or rocket, but had no other details.
The attack comes as the US announced that it will begin talks with top Taliban emissaries to discuss a long-term peace plan for Afghanistan.
Earlier in the day, American and allied forces had formally handed over control of the country's security to the Afghan army and police in a ceremony in Kabul. The transition to Afghan-led security means US and other foreign combat troops will not be directly carrying the fight to the insurgency, but they will advise and back up the Afghan forces as needed with air support and medical evacuations.
Additional reporting by Associated Press