A charity last night warned that thousands more children face an agonising death in the wake of the South Asia earthquake.

An estimated 20,000 children were among more than 54,000 people who died in the devastating quake on October 8.

But Plan, the international development agency for children, predicted a second and equally deadly crisis for those who survived.

Marie Staunton, Plan's UK chief executive, said: "The danger is far from over for the thousands of children who escaped death in the initial destruction and they are now more vulnerable than ever.

"For over a week many have had no shelter or warm clothes, very little fuel to keep them warm, insufficient food and little or no medical attention.

"Night time is extremely cold in the foothills of the Hindu Kush and, as winter sets in, the temperatures will soon drop below freezing.

"There are already reports of children shivering and being huddled around small campfires as fuel supplies dwindle."

Plan's director in Pakistan, Mia Haglund Heelas, said rain, snow, freezing nighttime temperatures, disease, and untreated injuries were taking their toll.

She said: "We have already seen cases of pneumonia and other respiratory infections in young children. We now fear that the number of cases will rise dramatically as the temperatures continue to plummet and children become increasingly weakened by under-nourishment and continued exposure."

The agency said it was impossible to know how many injured children were awaiting rescue in isolated communities.

"Our fears are that the children will die of minor injuries that could have been treated with early medical attention," Ms Haglund Heelas said.

"We know that the longer time goes on, the more children will die or require limbs amputated because of serious infection.

"All we can do is work as fast as we can to get to them."

More than £15 million has so far been pledged by British donors to help the devastated region.

The Disasters Emergency Committee (DEC) has urged the public to keep donating.

The United Nations Office for the Co- ordination of Humanitarian Affairs said the most critical challenge is the logistics of delivering shelter that will stand the harsh winter conditions.

Tents are said to be "like gold dust" on the Pakistani open market in villages where not a single house remains standing.