Hundreds of demonstrators on Wednesday attempted to storm a NATO camp in north-western Afghanistan manned by Spanish troops, witness reports said.
The residents in Badghis province protested at the Provincial Reconstruction Team's base after allegations that foreign troops had shot and killed an Afghan policeman, Mohammed Rahim told the German Press Agency dpa.
"Firing is continuing in the city, everyone is escaping, and thousands of people are trying to attack the Spanish PRT base," he said.
One Afghan policeman was killed and three Spanish soldiers were wounded in an earlier firefight in Qala-I-Naw, the provincial capital, reports said.
The NATO-led International Security Assistance Force (ISAF) said it had no information about the incident but were looking into reports, a NATO spokesman said.
A spokesman for the Afghan Interior Ministry confirmed the incident but said an investigation as ongoing.