Kabul - At least two people were killed and six others wounded when police opened fire on protesters blocking a highway linking eastern Afghanistan to Pakistan, witnesses said Saturday.

Hundreds of protesters blocked the highway in Shinwar district of eastern Nangarhar province protesting against the alleged killing of civilians by US-led coalition forces on Friday night.

The protesters brought the corpses of three "civilians" on the highway connecting Kabul to the Pakistani border, while chanting slogans against the Afghan government and foreign forces in the country.

Police opened fire after the protesters turned violent and threw stones, witnesses said.

According to one witness, at least one policeman was injured by the stonethrowers.

"Police opened fire on the protesters, killing two of them and wounding another six men," he said, adding that the police withdrew from the area and provincial authorities arrived at the scene to talk to protesters.

Provincial authorities refused to comment on the demonstrations or the killings.

US-led Coalition forces meanwhile said in a statement that their forces killed "several militants" and detained nine others on Friday in Shinwari district.

It said that the combined forces were searching the compounds when they came under fire by militants. The combined forces also discovered several AK-47 assault rifles, a bolt action rifle, ammunition and grenades on the compounds, the statement added. (dpa)