A suicide bomber riding a motorcycle has blown himself up outside the largest U.S. base in Afghanistan, Afghan officials say.
The Taliban claimed the September 6 attack was in revenge for a U.S. leaflet deemed highly offensive to Muslims.
U.S. and Afghan authorities confirmed several people were wounded in the late afternoon attack at Bagram Airfield, some 55 kilometers north of Kabul.
The Taliban claimed responsibility and said it was in retaliation for the authorities' "insult to the Islamic creed."
A spokesman for the governor of Parwan Province, where Bagram is located, said that "a suicide attacker on a motorbike detonated himself at the third gate of Bagram air base."
"The attacker was riding a motorcycle. Three wounded can be confirmed," Interior Ministry spokesman Najib Danish said.
NATO's Resolute Support mission said in a statement that "an explosion" had occurred "outside an entry-control point" to Bagram that had caused a "small number of casualties."
Taliban spokesman Zabihullah Mujahid claimed the attacker had killed and wounded "over 20 soldiers."
The incident came hours after U.S. forces apologized for dropping leaflets in Parwan Province that Deputy Governor Shah Wali Shahid said included an image of a dog carrying the Taliban flag.
The Islamic statement of faith -- "There is no God but Allah, and Muhammad is the messenger of Allah" -- was superimposed on the dog's body.
Major General James Linder, who heads the U.S. and NATO special-operations forces in Afghanistan, issued a statement apologizing for the leaflet design, which he said was an "error."
NATO forces frequently drop leaflets over large swaths of Afghanistan in an effort to persuade locals against supporting insurgents.