At least four American soldiers have been killed, following a suicide bombing at Bagram airbase, in Afghanistan.
A suicide bomber has killed four Americans inside Bagram airbase, the largest US military facility in Afghanistan.
US Defence Secretary Ash Carter said two members of the armed services and two contractors had died in the attack.
A further 16 US service members and one Polish soldier were injured, he added.
The Taliban said one of their fighters had carried out the attack, a major security breach in one of the best protected places in Afghanistan.
Bagram has been targeted by militants in the past but this is the first time a bomb has exploded inside the base.