PESHAWAR: At least 18,000 people have fled their homes in Pakistan's tribal district of Khyber, fearing a fresh onslaught of fighting between the army and Islamist militants, officials said Tuesday.

Families streamed out of the district, a flashpoint for Taliban and other violent groups on the Nato supply line into neighbouring Afghanistan, after the army ordered them to leave because of military action going on in the area.

Three Pakistani soldiers and 34 militants were killed in Khyber last week shortly before US Secretary of State Hillary Clinton arrived to step up pressure on Islamabad to do more to eliminate militant safe havens.

“Around 3,200 families, up to 18,000 people, have arrived in the Jalozai refugee camp and we are making arrangements to facilitate them,” Adnan Khan, spokesman for the disaster management authority of Khyber Pakhtunkhwa province, told AFP.

“We will provide them food for 15 days initially and also non-food items, including tents and utensils,” he said.

An administration official in Khyber said that many people were sheltering with relatives or in rented houses, rather than at the government camp.

“More than 20,000 people have left the area, many of them have gone to relatives' homes in Peshawar and other peaceful cities while many others rented houses there,” said Mutahir Zeb, the top administrative official of Khyber.

The United Nations said the numbers were being verified, but warned that the figure could be inflated by some people taking advantage of the free food and shelter on offer.

“The provincial disaster management authority has registered 3,200 families and we are verifying this number,” Dunya Aslam Khan, spokeswoman for the UN refugee agency, told AFP.

“The estimated numbers of the displaced people are likely to come down by 10 per cent because normally people who are not affected by the disasters also join the displaced families just to enjoy the benefits and compensation,” she said.

Pakistan's seven tribal districts on the Afghan border are rife with homegrown insurgency, and are strongholds of Taliban and al Qaeda operatives.

Although Pakistan has fought Taliban militants across much of the region, it has withstood US pressure to wage battle against the al Qaeda-linked Haqqani network, which has leadership bases in North Waziristan.