KABUL • Afghan forces scrambled yesterday to beat back the Taleban from Sangin as the insurgents claimed to have captured nearly the entire opium-rich district, following the first British deployment to the region in 14 months.

The militants broke through the front lines of Sangin on Sunday after days of clashes with besieged Afghan forces, tightening their grip on the province of Helmand.

Fleeing residents reported Taleban executions of captured soldiers as the insurgents advanced on the district centre, compounding fears that the entire province was on the brink of a security collapse.

Government officials yesterday denied reports that Sangin was on the brink of falling to the Taleban, saying reinforcements were trying to relieve dozens of security forces holed up in the district centre.

"Afghan army commandoes and police forces have launched an operation in Sangin," said interior ministry spokesman Sediq Sediqqi, claiming heavy Taleban losses.

But Taleban spokesman Zabiullah Mujahid claimed insurgents had overrun the entire district, pinning down Afghan forces in a military base where trapped soldiers reported dire conditions.

The war in Helmand, seen as the epicentre of the insurgency, follows a string of Taleban victories after Nato formally ended its combat operations last year. The turmoil in Helmand, the deadliest Afghan province for British and US forces over the past decade, underscores a rapidly unravelling security situation.

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. The deployment, in addition to a recent arrival of US special forces in the region, is the first since British troops ended their combat mission in Helmand in October 2014. US aircraft carried out two attacks in Sangin, officials said yesterday. Nato headquarters in Kabul confirmed the air strikes on Wednesday had taken place but gave no details.

Russia, meanwhile, has said it is ready to supply arms to Afghanistan. Interfax news agency quoted Russian special presidential envoy to Afghanistan Zamir Kabulov as saying: "We are ready to deliver weapons, but we will do it carefully and mainly on a commercial basis."

But he ruled out the possibility of Russian military operations there similar to the air strikes in Syria. "Afghanistan is not Syria and our air force is not going to operate there," he said on Wednesday.

AGENCE FRANCE-PRESSE, XINHUA