United Nations aid agencies are moving in food and medical supplies into the West Bank, as long as a lull in Israeli military operations continues in two towns.

U.N. relief agencies say that it is still difficult to reach most of the West Bank with needed food and medical supplies for the Palestinians. The Israeli army has pulled out of two West Bank towns, but has given no indication when it will withdraw from other cities and refugee camps. Israel launched its military offensive on the West Bank against Palestinian militants last month, in an effort to halt a wave of Palestinian suicide bombing attacks against Israelis.

Spokeswoman Wivina Belmonte of the U.N. children's agency said UNICEF sent convoys with aid to the West Bank towns of Bethlehem and Ramallah Tuesday.

"It's the first time that we have managed to get goods in since Friday. The convoy to Bethlehem includes 1,300 liters of milk, 600 kilos of flour, and the convoy that is destined to a government hospital in Ramallah is full of medical supplies," Ms. Belmonte said.

The U.N. agency for Palestinian refugees (UNRWA) has said on Monday, the Israeli army arrested one of its doctors and took over a school and hospital run by the agency, to use as a military post in the Bethlehem area.

UNRWA spokesman Rene Aquarone said Israeli military attacks in Jenin and Nabulus have been extremely heavy. He said that on Monday UNRWA tried to get its own ambulance through the checkpoints to help a patient bleeding to death in the Balata refugee camp in Jenin.

"We got clearance, we sent one of our own ambulances through. It was shot at and partially destroyed and that patient has been administered unchecked blood due the impossibility of doing lab tests on the donors," Ms. Aquarone said.

UNRWA has said it is attempting to bring blood, food, oxygen, blankets and tents to Jenin and Nablus, where fighting has been fiercest.

The World Food Program said it is hoping to distribute food aid to hospitals, orphanages and clinics as soon as it can gain access.

The World Health Organization has sent a fact-finding team to the region. WHO said it has not yet received a response from the Israeli government to concerns raised by its chief that WHO was being denied access to the injured and about the lack of guarantees for the safety of its medical staff.