Afghan forces clashed with taliban in spin boldak after launching an operation to retake the key border crossing, as regional capitals rush to get the warring sides talking.

Residents of spin boldak, which fell to the taliban on wednesday, said the taliban and army are battling in the main bazaar of the border town.

As fighting continued, pakistan said it would hold a special conference on afghanistan in islamabad.

There are signs that official talks in doha, which have stalled for months, could stutter back to life.

The taliban have capitalised on the last stages of the withdrawal of foreign troops to launch a series of lightning offensives across the country, capturing a swath of districts and border crossings, and encircling provincial capitals.