Pakistan on Tuesday sternly told the Taliban [Images] to leave Buner and other areas occupied by them or face "forceful" action, as its troops killed 70 militants in the expanding army operations along the restive Afgan border.

The warning that "a handful of militants cannot challenge the writ of the government," came from Interior Minister Rehman Malik as security forces stepped up operations in Dir in North West Frontier Province.

Backed by helicopter gunships and heavy artillery, Frontier Corps personnel blasted Taliban hideouts in the mountains of Kalpani and Akakheldara in Dir, killing 70 militants and seizing sophisticated arms and ammunition.

The fresh fighting triggered a mass exodus from various villages and towns of Dir with 30,000 people leaving their homes for provincial capital Peshawar and other towns.

"Up to 30,000 people have left Maidan in Lower Dir district over the past few days," NWFP Information Minister Mian Iftikhar Hussain said.

Malik, who was elevated to full cabinet rank on Monday, told media persons outside Parliament that the Taliban would have to leave Buner and other areas occupied by them.

The presence of militants so close to the federal capital had raised concerns in the US, which told Islamabad [Images] to take strong action to flush out Taliban and other militants.

Malik said he wanted to make it clear to Tehrik-e-Taliban chief Baitullah Mehsud that the government had been avoiding military action to prevent collateral damage.

He said the government had a policy to thwart the efforts of those who are trying to destabilise Pakistan.

"It is a fact that there is insurgency in some areas and the prime minister has given a 3D policy (of dialogue, development and deterrence) that is being implemented properly," he added.

He also dismissed fears about the safety of Pakistan's nuclear assets and the advance of the Taliban to the vicinity of Islamabad.

"All our nuclear assets are in the safe hands of competent people. We are a responsible nation that knows how to protect these assets," he said.

The unchecked advances of Taliban, which moved to about 100 km of Islamabad by taking control of Burner district just outside the capital region, has stunned the Obama [Images] administration.

Reacting to the Taliban's march towards other Pakistani cities from their stronghold in Swat, US Secretary of State Hillary Clinton [Images] said the US cannot even contemplate that and cannot let this go on any further.