A US soldier shot dead an Afghan guard outside a military base in northern Afghanistan, apparently believing he was about to attack him, a local official said Sunday.

The incident on Thursday in Sari Pul province came less than a fortnight after an Afghan soldier shot dead four unarmed French troops at a base in the east of the country.

"A US soldier has shot dead an Afghan guard three days ago", Sari Pul provincial security chief Sayed Jahangir said on Sunday.

"The American shot dead his Afghan colleague due to a misunderstanding. Apparently he thought the guard was trying to attack him."

The victim was named as 22-year-old Abdul Rahim. He had been newly appointed as a guard by a private security company, Jahangir said.

A spokesperson from NATO's International Security Assistance Force refused to comment when contacted by AFP, saying the investigation was ongoing.

The January 20 incident prompted French President Nicolas Sarkozy to say his country would end its combat role in Afghanistan by the end of 2013 -- instead of the planned NATO deadline of the end of 2014.

Violence between foreign and Afghan soldiers has been growing more frequent, and is increasingly linked to "cultural incompatibility" and arguments, rather than Taliban influence, according to a NATO report.