Afghan officials say around 100 soldiers fled their posts and tried to cross into neighboring Turkmenistan during a weeklong battle with the Taliban, in the latest setback for the country's battered security forces.

Mohammad Naser Nazari, a provincial council member in the western Badghis province, said Sunday the soldiers were not allowed to cross the border and their fate remains unknown. The Taliban have posted pictures of captured soldiers on social media.

Jamshid Shahabi, the provincial governor's spokesman, says 16 soldiers have been killed during the ongoing battle, in which the military carried out several airstrikes and dispatched reinforcements. He says a number of soldiers tried to flee, without providing an exact number.

The Taliban effectively control nearly half the country and attack Afghan security forces on a daily basis.