Half a million people have fled northwestern Pakistan in the past few days because of incessant fighting in the Swat region, bringing the total number of displaced residents to one million, the UN refugee agency said Friday.

The UN High Commissioner of Refugees estimates that up to 200,000 people have relocated to safe regions but that another 300,000 are still on the move or are preparing to flee.

About 555,000 have already fled Pakistan regions that border Afghanistan since August, spokesman Ron Redmond told reporters in Geneva on Friday.

Fighting along Pakistan's volatile border region in recent years has caused enormous destruction and significant civilian deaths. The country has launched at least a dozen offensives in the area, which is widely considered by foreign governments to be a haven for Taliban and al Qaeda militants.

In an effort to end one of the offensives, Pakistan agreed to a peace accord in Swat that allowed Islamic law in the region. However, the deal collapsed in April when Taliban fighters from Swat began to move into Buner, a neighbouring region located 100 kilometres from Islamabad.

Pakistan's prime minister promised yesterday in a televised speech to trounce the militants and asked the international community for help in dealing with the country's displaced residents.

"I appeal to the people of Pakistan to support the government and army at this crucial time," said Prime Minister Yousuf Raza Gilani. "We pledge to eliminate the elements who have destroyed the peace and calm of the nation and wanted to take Pakistan hostage at gunpoint."

The public's attitude towards the militants began to shift against the Taliban after the group didn't heed the peace deal but rather used it as an opportunity to regroup and advance, said the Pakistani army general.

"The public have seen their real face," said Maj. Gen Athar Abbas.. "They realize their agenda goes much beyond Shariah (Islamic) courts. They have a design to expand."

The military offensives have taken place in three districts that stretch over 1,000 square kilometres. Most of the fighting has taken place in Mingora, a main city in Pakistan's Swat Valley.

Around 360,000 people lived in the area before the insurgency began in 2007.

Tens of thousands of inhabitants still reside in the region. Some say they haven't fled because the Taliban is forcing them to stay and act as "human shields" in order to dissuade the Pakistani army from using force.

"We want to leave the city, but we cannot go out because of the fighting," said one resident, Hidayat Ullah, in an interview with the Associated Press. "We will be killed, our children will be killed, our women will be killed and these Taliban will escape."

"Kill terrorists, but don't harm us," he said.

Several soldiers and more than 150 militants were killed since the military began its latest operation last week. The military has not released a tally of civilian casualties but local media and witnesses have reported that they have occurred.

A hospital located just south of the battle zone in Mardan reported Thursday it was treating 45 civilians that had been seriously wounded with gunshots or shrapnel.

A 12-year-old girl, Chaman Ara, is among the youngest patients. She was admitted after a piece of shrapnel became wedged in her left leg.

She told the Associated Press that she was injured when a truck carrying her family and others was struck by a mortar shell. Seven people died as a result, including her cousin.

The girl pointed to her dead cousin's mother, laying wounded on a nearby bed, and said that the woman did not know her son's fate.

"We musn't tell her yet," she whispered. "Please don't tell her."

The vehicle was carrying the civilians out of Buner.

With files from The Associated Press