The thump of artillery shells could be heard on Wednesday in the main town of Miranshah, coming from the vicinity of Mir Ali, a town 25km away.
|Civilians have been streaming out of Mir Ali|
and other towns caught in the fighting
Scores of rounds were fired in the pre-dawn barrage, residents said.
Mir Ali has a reputation as a Taliban and al-Qaeda stronghold, but many of the residents say they have nothing to do with either group and were just caught in the crossfire.
Fighters also fired a couple of rockets on to the military runway near Miranshah's fort, but there were no casualties reported.
About 1,500 people gathered in the village of Epi on Wednesday, hoping to bury those killed in the previous day's air strikes.
A local religious leader described Epi as a ghost town whose residents had run for their lives when the bombing began.
He said some of the victims were found lying in the street or in the rubble of destroyed houses and shops.
"Pakistan needs a military leader who can control both civil and possible military extremism"
Creative_person01, Islamabad, Pakistan
Send us your views
Residents of Mir Ali are arriving in their dozens at a hospital in Bannu, a town 50km east of Epi.
Many have serious injuries.
Describing how members of his family were killed, Mohamed Zubair, a resident of Mir Ali, said: "F-16 fighter bombers dropped their payload on our homes. Also heavy artillery was used from the Mir Ali military camp.
"We lost four women and four males in our home while 14 to 15 were wounded who were rushed to Bannu."
He said: "We have no Taliban in our homes. We are not close to the military camp but we were still targeted by mortars."
Origin of clashes
The fighting began in North Waziristan on Saturday after an army convoy was ambushed near Mir Ali.
On Tuesday a bomb exploded in a market in Peshawar, the capital of Pakistan's North West Frontier province.
The explosion wounded more than a dozen people and shops were destroyed.
Pakistani fighter jets then pounded positions in the area, causing thousands to flee anyway they could.
North Waziristan has long been a volatile area and violence in these parts is not uncommon. But these past few days has seen the heaviest fighting in months.
Pakistani soldiers and paramilitary troops have been targeted by suicide bombers, blown up by roadside bombs, kidnapped and had their throats slit.
Fighters in South Waziristan humiliated the army by taking captive about 250 soldiers in late August.
More than 25 were released later, but this week three were killed, and there were threats of more killings unless the army acceded to demands.
|For months now, Pakistani security personnel|
have been hounded by pro-Taliban fighters
Morale too has suffered among security forces stationed in North and South Waziristan.
Al Jazeera's Kamal Hyder in Islamabad said the entire area had been cut off for about one week.
"There are no supplies getting in, we are told there are water shortages, we are told there is no electricty in the area. It is a desperate situation indeed," he said.
"People are evacuating their wounded on beds.
"They are carrying those beds four people at a time, walking over very large stretches of territory, 50km sometimes, just to get to the nearest medical facility."