NATO-led troops opened fire on three students on a motorbike, killing two of them and wounding the third one in central Maidan Wardak province on Saturday, officials said.
The incident triggered a protest by dozens of angry locals, who closed the Kabul-Kandahar highway for two hours, demanding justice, said provincial governor's spokesman, Shahidullah Shahid.
The angry villagers were shouting "death to America" and asked the Afghan government to ensure justice and trail the murderers.
NATO-led International Security Assistance Force (ISAF) in a statement said two Afghan civilians were "possibly killed" when entered a fighting area in Maidan Shahr, the provincial capital.
"A coalition unit was on a patrol when they were attacked by insurgents with an improvised explosive device," the statement said.
The troops had stopped the patrol to investigate the explosion when it came under small-arms fire, which forced the soldier to return fire, it added.
Three civilians on a motorcycle, ISAF said, entered the fighting area and were shot.
Foreign troops 'kill two students' in Wardak | Pajhwok Afghan News
