Military planes have dropped food and ammunition to besieged Afghan forces battling to push Taliban insurgents out of Sangin, officials said on Tuesday, two days after the emboldened militants stormed the opium-growing district.
Islamists have captured large swathes of the district in the southern province of Helmand which British and US forces struggled for years to defend.
Fleeing local residents reported bloody gunfights as the Taliban advanced on the district centre, highlighting a worsening security situation across Afghanistan a year after NATO formally ended its combat operations.
"We are air-dropping food supplies, military equipment and ammunition to support our forces in Sangin," defence ministry spokesman Mohammad Radmanesh told AFP.
"Sporadic fighting is going on around the district," he said, rejecting reports of high military casualties and asserting that the district had not fallen to the Taliban.
A resident who fled Sangin told AFP that insurgents had publicly executed at least three security officials after storming government buildings.
"The Taliban dragged two intelligence officials and a local police commander from their homes and shot them dead," Haji Abdul Qader told AFP.
"Only the governor's compound and the police headquarters are under government control. The rest have been overrun by the Taliban."
Qader said he fled to the Helmand provincial capital lashkar Gah after a mortar bomb landed on his
house, wounding his infant son and daughter.
His testimony bore chilling similarities to the situation in Kunduz after the Taliban briefly captured the northern city in September — their most spectacular victory in 14 years of war.