The death toll in Friday's airstrike was determined after a site inspection of the compound in the Gereshk district, he said.

The United States in a statement confirmed that the airstrike on the Security Forces compound happened during a US-supported operation against Taliban insurgents in the area. In the statement the US offered its condolences to the families of the security forces who were killed.

While much of Helmand province is under the control of Taliban, Afghan national security forces have been waging fierce battles to retake territory. NATO and US troops are in Helmand to assist Afghan troops.

Safi told The Associated Press in a telephone interview that the dead were police officers who were operating with the army in the area. He said they had recaptured the post from the Taliban when the airstrike occurred. On Friday, the Helmand Governor Hayatullah Hayat said it was believed the police officers were not in uniform, which may have resulted in mistakenly identifying them as Taliban fighters.

Elsewhere in Afghanistan, in northern Badakhshan province Governor Ahmad Faisal Bigzad said Saturday that 11 police were killed and another six wounded during a roaring battle with Taliban insurgents in the remote Tagab region.

Bigzad said another 20 members of a local police force were missing following Friday's firefight. It wasn't immediately clear if they had been kidnapped or had escaped.

The area in which the fighting occurred is tucked inside a mountainous region where access is restricted and even telephone contact is erratic.

In western Farah province, a ferocious gun battle between the Afghan army and Taliban insurgents left six Afghan soldiers dead and 12 Taliban killed, said Mohammad Naser Mehri, spokesman for the provincial governor.

The five-hour battle Friday occurred after Taliban insurgents stormed a compound of the Afghan National Security Force in Pusht Rod district, he said.

A Taliban statement meanwhile claimed a victory and said 16 Afghan soldiers were killed. Taliban have in the past exaggerated their successes and the remoteness of the area made it impossible to independently verify.