"We told the Pakistani delegation that Islamabad is not in a position to play any role of mediator between us and the Taliban. We said Pakistan is not neutral in Afghanistan's conflict and can't be an arbitrator,'' Younis Qanooni, a top aide for Gen Masood, told Reuters.

Pakistani Foreign Ministry Envoy Rustam Shah Mohmand travelled to Dushanbe for talks with the anti-Taliban alliance about the mediation offer.

Mohmand, a former commissioner for Afghan refugees based in Pakistan, enjoys good relations and respect among Afghanistan's warring sides, including Gen Masood.

He was also expected this weekend to meet the Taliban leadership in its stronghold in the southern city of Kandahar and discuss Pakistan's offer and also opposition view about finding a solution to thecountry's two decades of war.

Fighting between the Taliban and Gen Masood's forces has flared up on several fronts recently.

The fighting, the worst in more than ten months, started late last month when the Taliban launched a massive offensive to wipe out Gen Masood, its last potent foe.

Observers say both sides have suffered high numbers of casualties in the seesaw battle north of Kabul and in fronts in the eastern part of the country near Pakistan.

The Opposition says about 5,000 Pakistani regular forces and volunteers are involved in the fighting, which has been denied by the Taliban and Islamabad.

"We explicitly protested in the meeting against the involvement of these Pakistani nationals," Qanooni said.

The latest fighting also comes after the failure last month of UN-sponsored peace talks between Gen Masood and the Taliban in Tashkent.

Pakistan is one of only three countries that recognise the Taliban as the government of Afghanistan and has staunchly denied charges that it arms andsupplies the Taliban.

Pakistani madrassas were the birthplace of the Taliban movement, which says it is going to build the world's purest Muslim state after crushing Gen Masood.

The Taliban say that Gen Masood, the military Chief of the government the movement toppled in 1996, must surrender and join their self-styled Islamic emirate of Afghanistan.

But Gen Masood, an ethnic Tajik, says an interim government should be formed first and opposes domination by the Taliban, who are from the Pashtun ethnic group.