“US forces conducted two strikes in Sangin,” a Nato spokesperson said in a brief statement.
Dozens of militants were killed in a parallel army clearance operation, including a key commander seen as a close confidante of Taliban leader Mullah Akhtar Mansoor, the interior ministry said.
Taliban claim to have captured nearly the entire district of Sangin after storming its frontlines last Sunday, tightening their grip on the southern Helmand province.
Fleeing residents reported that the Taliban were executing captured soldiers as the insurgents advanced on the district centre, compounding fears that the entire province was on the brink of falling into insurgent hands.
The US army conducted the air strikes on Wednesday to support Afghan forces mobilising reinforcements to relieve dozens of security forces holed up in the district centre. It followed the first British deployment to the volatile region in 14 months
But Taliban spokesperson Zabiullah Mujahid claimed that the insurgents were in control of the whole district, pinning down Afghan forces in an army base where trapped soldiers reported dire conditions.
“Our men are hungry and thirsty,” Abdul Wahab, a local police commander in Sangin, told AFP.
“Stepping out to get bread means inviting death,” he said, adding that dozens of his comrades had been killed and critically wounded.
The war in Helmand, seen as the epicentre of the expanding insurgency, follows a string of military victories for the Taliban after Nato formally ended its combat operations last year.
All but two of Helmand’s 14 districts are effectively controlled or heavily contested by the Taliban, who also recently came close to overrunning the provincial capital of Lashkar Gah. The turmoil in Helmand, the deadliest province for British and US forces in Afghanistan over the past decade, underscores a rapidly unravelling security situation in Afghanistan mandating a refocus for international troops still stationed in the country.
Britain on Tuesday said a small contingent of its troops had arrived in Camp Shorabak, the largest British base in Afghanistan before it was handed over to Afghan forces last year.