Three people were killed after a lone suicide bomber struck at a US base in eastern Afghanistan on Wednesday.
But authorities say the attacker did not get breach its perimeter of the base.
The Afghan Taliban has claimed its bomber drove a vehicle packed with explosives to the base in Khost, 150 kilometres from the capital Kabul.
Eyewitness Anwarullah Khan said: “There was a big bang which wounded some people. I don’t know the exact number of wounded but it was really powerful.”
The base is believed to be used by the CIA.
A suicide attack there three years ago killed eight intelligence officers.
Wednesday’s blast comes as NATO-led troops prepare to withdraw from Afghanistan in 2014.
The three dead where Afghan civilians.