Pakistani troops are continuing to shell Taliban positions since launching the latest offensive under US pressure after the fighters moved into Buner, within 100km of the capital Islamabad.
Robert Gates, the US defence secretary, appealed to congress to disburse money for military aid to Pakistan as fighting raged.
Islamabad is central to Washington's strategy for stopping the Taliban's resistance in neighbouring Afghanistan.
Al Jazeera's Kamal Hyder, reporting from just outisde Buner, said the Taliban has been offering "some resistance" in Buner.
"The military have used assault helicopters on those positions where the Taliban fighters are said to be based, and they are said to be facing stiff resistance," Hyder reported.
"I can't sleep in my bedroom because my house keeps rattling all night due to heavy shelling"
Habibulah Khan, resident of Buner
"This has also led to fears within the area that the Taliban had also planned for the military as they move in. The military spokesman admitted that there were IEDs [Improvised Explosive Devices] placed along the road and were slowing the military movement."
But the military spokesman said the troops were careful not to go on a heavy assault because of the fear that there would be civilian casualties, Hyder reported.
Civilians in Buner said on Friday that the fighting was heavy.
"I can't sleep in my bedroom because my house keeps rattling all night due to heavy shelling," Habibulah Khan, a local resident, said.
Hazrat Khan, 26, a teacher in Sultanwas, said he, his wife and four children had been holed up at home for four days, with food running low.
"I can see through chinks in the door that Taliban are everywhere out there. I can't move because of the curfew and shelling. I appeal to the authorities to evacuate us," he said.
The Pakistan government ceded control of the nearby Swat valley in February, signing a deal to allow religious hardliners to enforce Islamic law in the region in order to end a bloody two-year rebellion led by a radical cleric.
But the Taliban pushed further south towards Islamabad instead of disarming, taking control over swathes of Lower Dir and Buner and triggering the latest offensive.
Earlier on Friday, more than 50 armed Taliban stormed a local paramilitary headquarters in Upper Dir - a district so far shielded from the military offensive - and snatched 10 security forces personnel, officials said.
The 10 were freed unharmed later in the day.