However, official with the U.S.-led military coalition operating in the area and a diplomat say no Americans were killed in the blast.
Shafiq Hamdam, with the International Security Assistance Force's regional command East told CBS News a suicide bomber in a car did hit a U.S. convoy Friday morning near a market, but only four U.S. soldiers were slightly injured and one vehicle was damaged.
A Western diplomat who knows the area well told CBS News he had contacted the Afghan government's military commander in the area, who confirmed that a man driving a white Toyota Corolla had rammed into a U.S. convoy, but the only death was the suicide bomber. The diplomat spoke to CBS on condition of anonymity.
Sky News's Alex Crawford, reporting from neighboring Pakistan, said the governor of Nangarahar province and other local officials had confirmed a suicide attack on a U.S. convoy near the Marko Bazzar in the volatile border area.
Mullah Shokoor, a Taliban commander who says he is the head of suicide operations for the Tora Bora region of Afghanistan, contacted CBS News Friday and said one of his bombers had carried out the attack.
He claimed two U.S. military vehicles were "badly damaged and 14 to 15 soldiers killed." The Taliban often greatly exaggerates its claims referring to attacks on Western troops.
Shokoor said the bomber was an Afghan man from Kunar province. He also said his brigade "has dozens of willing bombers" and promised continued attacks.
A local journalist in the area who visited the scene of the blast also told CBS News that only the bomber appeared to have been killed, and there were no apparent civilian casualties.
A statement found by CBS News on a Taliban Web site referred to an attack on Jalal Abad Torkham highway in Nangarahar province. The location matches the scene of the popular Marko Bazzar.
"Our brother said Allahu Akbar (God is great) and exploded his booby-trapped car at a convoy in which two tanks were destroyed and nine American soldiers in the tanks were killed," the Taliban Internet statement said.
In the statement, the author first referred on two occasions to an "Armenian" contingent being attacked, before claiming that "American soldiers" were killed.
The reference to Armenia was likely a typo, as there are no Armenian soldiers participating in the International Security Assistance Force (ISAF) - the military coalition operating in Afghanistan.
The Internet statement was attributed to Zabihullah Mujahid, a Taliban spokesman.