KANDAHAR - A US air raid has killed eight Afghan policemen who were battling the Taliban, officials said Monday, the first apparent “friendly fire” incident since American forces were given greater powers to strike at insurgents.

The incident happened on Sunday in the Tali area of Uruzgan province. The Taliban recently attempted to overrun the provincial capital Tarin Kot in a major security breach.

“The first air strike killed one policeman. When other policemen came to help, they came under a second air strike, killing seven of them,” Rahimullah Khan, highway police commander in the southern province, told AFP.

Mohammad Sediq, a policeman who survived the attack, said their forces were “engaged in close fighting” with the Taliban when they were bombed.

The NATO command centre in Kabul confirmed US warplanes had conducted an air strike in the area, but said they targeted individuals posing a threat to Afghan forces.

“US forces conducted two air strikes against individuals firing on... our Afghan partners in Tarin Kot on 18 September,” NATO spokesman Charles Cleveland said in a statement.

“We don’t have any further information on who those individuals might have been or why they were attacking (Afghan) forces. US, coalition, and Afghan forces have the right to self-defense, and in this case were responding to an immediate threat.”

The policemen “were inside their checkpoint” when they came under US bombardment, Mohammad Karim Khadimzai, the head of Uruzgan’s provincial council, told AFP.

Civilian and military casualties caused by NATO forces have been one of the most contentious issues in the 15-year campaign against Taliban insurgents, prompting harsh public and government criticism.

A US air strike killed up to 10 Afghan soldiers in July last year at an army checkpoint in Logar province south of Kabul, one of the deadliest episodes of “friendly fire” by foreign forces in recent years.

NATO officially ended its combat mission in December 2014. But US forces in June were given more power to strike at the insurgents as President Barack Obama vowed a more aggressive campaign.

The new authority gave the US-led NATO troops greater latitude to order air strikes in support of Afghan troops.

Earlier this month Afghan forces backed by US air strikes mounted an offensive to flush out Taliban insurgents encircling Tarin Kot.

Afghan forces repelled the attack hours later, bolstered by reinforcements.

Uruzgan, a remote province with a huge opium industry, is one of the biggest flashpoints in the Taliban insurgency that erupted after a US-led invasion brought down their regime in 2001.

While “friendly fire” incidents involving foreign coalition forces are a volatile issue in Afghanistan, UN statistics show that the Taliban are responsible for most deaths.