(RFE/RL) -- The UN refugee agency says 500,000 people have fled fighting in northwestern Pakistan in the past few days.
It also warns that the military offensive against militants in the Swat Valley would lead to a total of 1 million people eventually being displaced.
The UN High Commissioner for Refugees (UNHCR) said up to 200,000 people had escaped the renewed violence, reaching safer zones.
UNHCR spokesman Ron Redmond told reporters in Geneva that another 300,000 are on the move or are about to flee. The numbers are in addition to 555,000 already counted by the UN since August.
A full-scale offensive is currently under way with helicopter gunships blasting militant strongholds from the air and troops conducting operations on the ground.
"There was extremely heavy bombardment in Swat. My village and the entire area around it was destroyed," said Amanullah Khan, a refugee who escaped from Swat three days ago. "In front of my eyes 45 to 50 people were killed by the bombing. They died, they were blown to pieces."
Redmond said UNHCR teams were reporting that the roads out of the Swat and Buner regions were "full of traffic" as people fled.
UNHCR was setting up centers along the roads to provide the refugees with food and water, and working on arranging camps and other humanitarian assistance.
On May 7, Pakistani Prime Minister Yusuf Raza Gilani vowed to eliminate terrorists from Swat, a bastion of Taliban rule, saying, "In order to restore the honor and dignity of our homeland, and to protect our people, the armed forces have been called in to eliminate the militants and terrorists."
The government has appealed to the militants to disarm, which they say was agreed in a three-month-old peace deal between the Taliban in Swat and government officials.
But Khan, like many Pakistanis, expressed misunderstanding about the government's actions.
"Once they [the government] started a [military] operation; then they signed a peace deal; then again they started an operation," he said. "We don't understand what game they are playing."
compiled from agency reports