UNITED NATIONS, United States (AFP) -- Palestinians are "facing a precipice" in Gaza, the top UN refugee official there told the Security Council on Thursday in a strongly-worded appeal for action.
With more than 220,000 Palestinians already sheltering in UN facilities -- four times the number from the last Gaza conflict in 2008-2009 -- Philippe Krahenbuhl said he had reached breaking point.
"I believe the population is facing a precipice and appeal to the international community to take the steps necessary to address this extreme situation," the head of the UN Palestinian refugee agency UNRWA told the 15-member council.
"We have exceeded the tolerable limit that we can accommodate," Krahenbuhl said, adding that he was "alarmed" by the latest Israeli instructions to civilians to evacuate two areas in Gaza targeted for more attacks.
"It is past time for an immediate and unconditional ceasefire as called for by the council," he said.
Krahenbuhl spoke to the council by audiolink from Gaza after Israel vowed to press on with its military campaign to destroy a network of tunnels used by Hamas militants for attacks.
International alarm has grown over the civilian death toll from 24 days of fighting between Israel and Hamas in the Gaza strip, with the Security Council calling for a humanitarian truce in a statement issued early Monday.
In her address to the council, UN humanitarian aid chief Valerie Amos called for "more humanitarian pauses" to allow relief workers to reach those in need.
"Pauses must be daily, predictable, and adequate in length so that humanitarian staff can dispatch relief to those in need, rescue the injured, recover the dead and allow civilians some reprieve so that they can restock and resupply their homes," she said.
Amos said finding shelter from Israeli strikes was becoming increasingly difficult for the 1.8 million people of Gaza.
"The reality of Gaza today is that no place is safe," she said.
More than 1,300 Palestinians, mostly civilians, have died in the fighting, along with 58 Israelis, most of them soldiers.
The appeal to the council came a day after an attack on a UN-run school hosting refugees left 19 dead, drawing outrage from UN Secretary General Ban Ki-moon who lashed out: "Nothing is more shameful than attacking sleeping children."
UN officials have said they believe an Israeli artillery strike hit the school and have called for a full investigation.Appalling conditions in UN shelters
Krahenbuhl described dire conditions for the shelters with very few showers and latrines, and problems with water supplies in classrooms holding 80 people.
"Disease outbreak is beginning" with cases of skin infections such as scabies while thousands of pregnant women have taken refuge in the UN schools, he said.
"We are sheltering newborn infants in these appalling conditions," said the head of the United Nations Relief and Works Agency for Palestinians.
"The illegal blockade of Gaza must be lifted," he added, referring to Israeli closure of crossing points that rights groups maintain have turned the Gaza Strip into an "open prison."
Palestinian representative Riyad Mansour renewed his appeal to the Security Council to adopt a tough resolution calling for an end to the fighting, an Israeli withdrawal from Gaza and lifting of the Israeli blockade.
"Enough is enough, this genocide should be stopped immediately," Mansour told reporters after the council meeting.
Jordan last week circulated a draft resolution, but the council has yet to debate the measure and has instead adopted a statement calling for the humanitarian truce.
The statement was adopted despite reservations from the United States which was hoping to give diplomatic efforts a chance to yield results in the region.
Israeli Ambassador Ron Prosor told reporters that Israel had agreed to "every humanitarian ceasefire" in the conflict and renewed accusations that Hamas was using civilians as shields.
He showed aerial photographs of Hamas rocket launch sites, saying these were close to schools. "Nothing is off-limits for Hamas," said Prosor.