In the neighbouring district of Bajaur, armed men took over a house killing at least one civilian and injuring several women, security sources said.

The clashes in the tribal areas come as soldiers in Buner district, just 100km northwest of the capital, Islamabad, battled pro-Taliban fighters.

Buner curfew

A curfew is in place in the region after about 100 people were killed in a four-day period up to Friday. Hundreds of civilians have fled the area.

Al Jazeera's Sohail Rahman, reporting from Islamabad, said: "Large groups of civilians are getting out of there if they can ... to two camps that have been set up in the south of Buner district out of the main conflict zone.

"We have to defeat these negatives forces, the forces of terror and those forces who are creating chaos among us"

Shah Mehmoud Qureshi,
Pakistani foreign minister

"The army has raised the ante over the past 72 hours," he said.

"We have seen heavy artillery, tanks and helicopter gunships encircling the areas of Swat, Dir and Buner - and as that military offensive continues it can be expected that those sympathetic to the Taliban will attack the military."

Pakistan's army said on Friday that it had fought its way over a mountain pass into Buner, a hilly farming district beside the Indus River, and was
bombing the fighters' bases further north.  

The fighters moved into Buner after an agreement between the government and pro-Taliban groups to allow a stricter implementation of sharia (Islamic law) in the Malakand Division - which includes Swat, Lower Dir and Buner - in exchange for peace.

Sufi Muhammad, an influential local scholar, was meeting officials on Saturday to discuss the deal, which Pakistani military officials say has been broken by the continuing violence.
 
Shah Mehmood Qureshi, Pakistan's foreign minister, has urged religious scholars to help end the violence by opposing pro-Taliban fighters.

"We have to defeat these negatives forces, the forces of terror and those forces who are creating chaos among us," he said in the central city of Multan.

"We will confront you at every hill, we will face [you] at every ideological trench and, God willing, we will defeat you."

'Prudent move'

Meanwhile, The New York Times newspaper reported on Saturday that the administration of Barack Obama, the US president, had reached out to Nawaz Sharif, a prominent Pakistani opposition leader, in an attempt to improve security. 

Citing unnamed administration officials, the newspaper said on its website the move reflected heightened concern in the White House about the ability of the Pakistani government to survive in the faltering security situation. 

Talat Masood, an Islamabad-based political analyst and former Pakistani general, told Al Jazeera that it would be "a very prudent move".

"It is very important that if you want to fight this war on terror you have to get [Sharif] on the right side," he said.

"He is in control of the province of Punjab which is the most important and vital province of Pakistan ... I think that the Americans are doing a very wise thing because if he stays out I think it will be very difficult to win this war against the Taliban."

The report came before a planned meeting between Obama, Hamid Karzai, the Afghan president, and Asif Ali Zardari, his Pakistani counterpart, on Wednesday.

Robert Gibbs, the White House spokesman, said: "The president looks forward to discussing with these two democratically elected leaders how we can work together to enhance our co-operation in this important part of the world as the United States implements a new strategy."