Maulana Yousaf Shah cracks a wide smile as he rattles off a list of former students turned Taliban leaders, revelling in their victories over superpowers on Afghanistan's battlefields after graduating from Pakistan's "university of jihad". 

The Darul Uloom Haqqania seminary has churned out a who's who of Taliban top brass -- including many now on the hardline group's negotiating team holding talks with the Kabul government to end a 20-year war.

"Russia was broken into pieces by the students and graduates of Darul Uloom Haqqania and America was also sent packing," beamed Shah, an influential cleric at the seminary that critics have dubbed the "university of jihad".

"We are proud."

The sprawling campus in Pakistan's Akora Khattak, about 60 kilometres east of Peshawar, is home to roughly 4,000 students who are fed, clothed and educated for free.

It has sat at the crossroads of regional militant violence for years, educating many Pakistanis and Afghan refugees -- some of whom returned home to wage war against the Russians and Americans or preach jihad.

Despite its infamy in some quarters, it has enjoyed state support in Pakistan, where mainstream political parties are heavily boosted by links with religious factions.

This month, Darul Uloom Haqqania's leaders boasted of backing the Taliban insurgency in Afghanistan in a video posted online -- outraging the Kabul government, which is battling a surge in violence across the county as the US prepares to withdraw troops.

Seminaries like Haqqania "give birth to radical jihadism, produce Taliban and are threatening our country", Sediq Sediqqi, Afghan President Ashraf Ghani's spokesman, told AFP, demanding their closure.

Afghanistan's leaders argue that Pakistan's approval for the madrassas is proof that it backs the Taliban.

Shah scoffed at the notion the madrassa encouraged violence, but he defended the right to target foreign troops. "If someone armed enters your house and you are threatened... then definitely you will raise a gun," Shah said.

The seminary's late leader Sami-ul-Haq boasted of advising the Taliban's founder Mullah Omar -- earning him the moniker "the father of the Taliban". Haq later sent students to fight for the movement when it issued a call to arms during its rise to power in the 1990s.

The Haqqani network, the Taliban's ultra-violent faction, is named after the madrassa where its leader once taught and subsequent leaders studied.

Some Pakistani extremists who later attacked their own country have also been linked to the seminary, including the suicide bomber who assassinated former prime minister Benazir Bhutto.

Hardline madrassas received a major boost and an influx of cash during the 1980s when they served as de facto supply lines to the anti-Soviet jihad backed by the US and Saudi Arabia, and have remained close to Pakistan's security establishment ever since.

Pakistan Prime Minister Imran Khan's party has also lavished the Haqqania seminary with millions of dollars in return for its political support.