Afghan commanders involved in the assault on the Shah-e-Kot mountain range in eastern Afghanistan have said the Taliban commander leading the defending fighters has escaped.
The Afghans said Saif Rahman Mansour escaped just before Afghan forces overran three villages and a commanding ridgeline, effectively ending the 10-day battle.
US officials had repeatedly said the Shah-e-Kot area was surrounded by soldiers and that the only choice facing the al-Qaida and Taliban fighters defending the region was to "surrender or die".
However, a significant number of fighters managed to flee as Afghan forces advanced and most are believed to have crossed into neighbouring Pakistan.