Eight campaigners were killed and a candidate for parliamentary elections was injured in a NATO airstrike in northern Afghanistan Thursday, a provincial official said.

Abdul Wahid Khurasani, who is running in the Sep 18 parliamentary elections in the northern province of Takhar, was on his way to a gathering in the province's Rastaq district when NATO helicopters opened fire, the spokesman said.

'Eight civilians were killed and Khurasani and two other campaigners were injured in the attack,' Faiz Mohammad Tauhidi, spokesman for Takhar's provincial governor, told DPA.

NATO military spokesmen were not immediately available for comment.

The governor has dispatched an investigation team including a provincial police chief to Kewan, the remote area in Rastaq where the attack took place, Tauhidi said.