Pakistan ordered more troops into a battle with Taliban forces in the Swat Valley valley, northwest of the capital, Islamabad, on Thursday.
Fighting has intensified there and in other areas of the north-west.
Thousands of civilians are fleeing the area, with fighting especially heavy in the main town of Swat, Mingora.
The BBC reports half a million people are still trapped in the town, without water or electricity.
A curfew has again lifted to allow civilians to leave Swat and join thousands of others who have already moved into camps or gone further to the south.
Meanwhile, officials say the government may abandon a recent peace deal with the Taliban.
The agreement, struck in April, allowed the Taliban to impose strict Islamic law, or Shariah law, in the northwestern region in exchange for an end to fighting.