Several thousand anti-Taliban fighters are reported to be holding out against the Taliban in a remote valley with a narrow entrance - little more than 30 miles or so from the capital Kabul.

It's not the first time the dramatic and imposing Panjshir Valley has been a flashpoint in Afghanistan's recent turbulent history - having been a stronghold against Soviet forces in the 1980s, and the Taliban in the '90s.

The group holding out there now - the National Resistance Front of Afghanistan (NRF) - recently reminded the world of the valley's strength.

"The Red Army, with its might, was unable to defeat us... And the Taliban also 25 years ago... they tried to take over the valley and they failed, they faced a crushing defeat," Ali Nazary, the NRF's head of foreign relations, told the BBC.