By Paul Anderson
BBC correspondent in Islamabad
A video sent to the BBC's office in Pakistan shows in detail for the first time regrouping Taleban fighters roaming freely in southern Afghanistan.
US forces have been hunting Taleban remnants in the Afghan mountains
The Taleban sent the video - showing them preparing home-made bombs - after the release of a Turkish engineer they kidnapped six weeks ago.
It included crudely-shot footage of the kidnapping.
The coalition has just launched its biggest push against the Taleban and al-Qaeda, called Operation Avalanche.
There was also plenty more revealing material in the hour-and-a-half-long video starting off in what appears to be a Taleban bomb factory - a mud-and-brick hut, presumably in southern Afghanistan.
Inside, several men strap detonators and timing devices in the shape of cheap alarm clocks to artillery shells two-and-a-half-feet-long (0.75 metres).
Two years after the world was told the Taleban were a spent force, the reality looks different
Then it is night time and the fighters carry the missiles on their shoulders to an unknown location.
They lay them on a small bank, nose them in the direction of their target and cover them with branches.
Evidence the video is genuinely from the Taleban is in the fact that it includes footage of the moment a Turkish road engineer was kidnapped by their fighters.
He was released 12 days ago.
Since the Taleban were ousted two years ago, their forces have continually harried the American-led coalition hunting them.
The video - if indeed it is genuine - shows the forces the Americans and their allies are up against.
Even crudely armed, they are well-motivated and able to move freely in some parts of southern Afghanistan.