Four people have been killed after an explosion at a US airfield in Afghanistan.
US army general John Nicholson said another 14 people were wounded in the attack inside Bagram Air Field in Parwan province, north of Kabul.
He said the blast was caused by an "explosive device," and the incident is still under investigation.
An earlier statement from Nato's Resolute Support mission said the blast happened around 5.30am local time (1am GMT) and that "force protection and medical teams are responding to the situation".
The Taliban claimed responsibility for the attack, which it said was carried out by a suicide bomber inside the base.
Zabihullah Mujahid, a spokesman for the insurgent group, said the attack had been planned for four months.
The Taliban regularly fires rockets at Bagram from outside its perimeter.
Abdul Wahid Sediqqi, a spokesman for the governor of Parwan province, where the air field is based, said he had received reports of four dead and around 18 wounded in the attack.
Labourers employed at the base line up at the gates around dawn, he said, adding that an attacker could have been among the men entering the facility.
There was no immediate word on the nationalities of those killed and wounded.