At least nine Afghan police were wounded in the "erroneous" airstrike in Gereshk district. Photo: File

KANDAHAR: An Afghan airstrike killed 10 security forces in volatile Helmand province on Sunday, an official said, as the military attempts to push back Taliban insurgents.

At least nine Afghan police were wounded in the "erroneous" airstrike in Gereshk district and an investigation is underway, Helmand governor Hayatullah Hayat told AFP.

"The airstrike happened as Afghan forces were pushing to break through the Taliban frontline in the strategic area that has been the scene of heavy fighting over the past several days," Hayat said.

The incident, which was confirmed by the defence ministry, comes more than two months after a US airstrike killed 16 Afghan police and wounded two others in the same district, large parts of which are under Taliban control.

Most of opium-rich Helmand province is controlled or contested by the Taliban, who are heavily reliant on the proceeds of drug trafficking to fuel their insurgency.