Pakistan army's operations have left a million people displaced, including 140,000 people from Mohmand agency [EPA]
Over 20,000 Pakistani villagers have fled military operations against armed fighters in Pakistan's tribal region of Mohmand near the Afghan border, a government official and the army has said.
Major General Athar Abbas, an army spokesman, confirmed on Friday that military operations were under way in Mohmand.
"We are targeting militant hideouts there," he said, adding that he hoped the displaced would soon be able to return.
According to a UNHCR estimate, if the fighting intensifies then up to 90,000 people (or 10,000 families) could be displaced by the end of February.
Over the last few days, the United Nations High Commissioner for Refugees (UNHCR) has registered about 25,000 people displaced as a result of fresh military operations against insurgents in the country's northwest.
The fighting began on January 27, involving aerial bombing, artillery and ground troops.
Roshan Khan Mehsud, the region's government representative, said that about 100 fighters had been killed so far, and the army has suffered "some casualties".
He did not, however, mention any civilian casualties.
Mehsud said that the people displaced by the Mohmand operations are living in a government building and schools.
The UNHCR has established two new camps, which are mainly accommodating people who have been fleeing the Sagi and Dawezai areas of Mohmand.
They have been given tents and other relief supplies, including sleeping mats, blankets, and kitchen utensils, and warm clothes for children.
People are also receiving hot meals and provision of food rations is being discussed with World Food Programme (WFP).
There have been reports by people arriving at camps that some young and middle-aged men have had difficulty leaving the conflict zone.
The authorities are being urged to ensure that any screening activities to identify fighters do not prevent civilians from leaving the area for safety.
Pakistan's military has carried out several operations in the country's remote tribal regions bordering Afghanistan over the last three years.
It has claimed to have made significant gains against the fighters, though many hundreds of thousands of the displaced residents have yet to return.
There have been several accounts of civilian casualties and attacks by Taliban fighters in Pakistan remain routine.
Reporting independently in Mohmand and other border areas is not allowed by the army and is considered highly dangerous.
The US has been pushing Pakistan to take action against Taliban and al-Qaeda hide-outs in the northwest of the country.