LASHKAR GAH, Afghanistan — The last of the Afghan forces have pulled out of the strategic district of Musa Qala in southern Helmand Province, officials said on Saturday, months after the Taliban overran most of the district and kept them holed up in desert outposts.

The retreat, which had many politicians here mystified, was the latest blow to a province that had been teetering for months. Now, the resurgent Taliban insurgents either control or are contesting 10 of its 14 districts, extending the fighting to Babaji, a suburb so close to the provincial capital that residents of the city could hear the clashes at night.

Col. Mohammad Rasoul Zazai, a spokesman for the Afghan Army’s 215th Maiwand Corps in Helmand, said the military leadership had decided that it was more effective to pull out the remaining troops and reinforce bases elsewhere in the province.

“We don’t have troops in Musa Qala anymore,” Colonel Zazai said.

Other officials said the decision was made to avoid further casualties to a reeling force because the army units were under severe pressure from the Taliban, making reinforcement and resupply difficult.