TEHRAN, Iran (AP) - Afghanistan's fast approaching bitter winter could leave up to 100,000 Afghan children dead in the next few weeks, an international relief organization said as aid workers on Monday battled for more supplies and to immunize needy Afghans to prevent the spread of epidemics.

"Winter is approaching fast and we need to move in emergency supplies even quicker in order to help the most vulnerable, the Afghan children and women, to survive these very cold conditions," UNICEF Regional Director for the Middle East and North Africa, Thomas McDermott, told reporters in Tehran.

UNICEF estimates that up to 100,000 Afghan children could die if essential relief supplies are not made available in the next few weeks.

McDermott, in Iran to oversee UNICEF's Iran-based emergency operations in Afghanistan, said the relief organization's priorities in Afghanistan were to conduct an "immunization program to prevent the spread of epidemic diseases, reactivate social services and getting Afghan children back to school."

Epidemic diseases spreading through Afghan refugee camps near Iran have claimed the lives of hundreds of children in the past few weeks.

McDermott thanked Iran for an "excellent job" in caring for Afghan refugees, who number more than two million. He said Iran was the source for relief supplies and technical expertise for Afghan refugees.

UNICEF offices in Kabul and Mazar-e-Sharif had restored regular operations and international staff would return to Herat following security checks, McDermott said. The organization's offices in Jalalabad and Kandahar remained closed.

McDermott said a cargo plane carrying 30 million tons of relief supplies for Afghan children had landed in Mashhad, northeastern Iran, Sunday. The supplies included therapeutic milk, sweaters, mattresses and boots and would be trucked to Herat, in western Afghanistan, on Tuesday.

Since the crisis began, UNICEF has sent three convoys including 80 million tons of relief supplies from Mashhad to Herat, including medicine and health supplies, water purification tablets, jerrycans and blankets.

However, delivering relief aid has been a major problem for humanitarian staff, as many drivers have been reluctant to travel on mountainous, icy Afghanistan roads for fear of crossing paths with retreating Taliban forces.

Meanwhile, the U.N. refugee agency has made the first payment of a $ 1 million donation to Iran to prepare for the possible "large-scale organized return" home of Afghan refugees.

The agency's Tehran office said $ 366,000 was given to Iranian Interior Ministry officials Sunday.

It said over 113,000 Afghan refugees have returned since the beginning of 2001 through Dogharoun, Iran's main border crossing in northeastern Iran. The rate of return through Dogharoun has risen to more than 1,000 people per day.

Copyright 2001 The Associated Press. All rights reserved.