Taliban forces have captured Lashkar Gah, the capital of the southern province of Helmand, Afghan officials have said.

The loss of Helmand’s provincial capital comes after years of toil and blood spilled by US, UK and allied Nato forces.

Estimates suggest those countries lost some 800 troops over the decades-long war there.

The insurgents have also captured the capital of Zabul province as their lightning offensive in the south gradually encircles the government in the capital, Kabul.

The insurgents have taken more than a dozen provincial capitals in recent days and now control more than two-thirds of the country, just weeks before the US plans to withdraw its last troops.