Hatem Moussa, Associated Press
Smoke rises after an Israeli strike hit the offices of the Hamas movement's Al-Aqsa satellite TV station, in Gaza City, northern Gaza Strip, Thursday, July 31, 2014.

UNITED NATIONS — The U.N. humanitarian chief called Thursday for daily "humanitarian pauses" until a long-term cease-fire is reached between Israel and Hamas in order to deliver relief to hundreds of thousands in need in Gaza, rescue the injured, and give civilians a reprieve from the war.

Valerie Amos told the Security Council that the world has watched "in horror the desperation of children and civilians that have come under attack" in Gaza. Over 80 percent of the more than 1,300 Palestinians killed were civilians, including 251 children, she said by videoconference from Trinidad and Tobago.

"The reality of Gaza today is that no place is safe," Amos said, citing attacks on over 103 U.N. facilities, including one on a school Wednesday that killed 19 people and injured more than 100.

Pierre Krahenbuhl, head of the U.N. agency for Palestinian refugees, told the council by phone from Gaza City that UNRWA is overwhelmed trying to help more than 220,000 people who have fled to U.N. facilities seeking safety.

That is four times higher than the peak number of displaced people in the last Gaza conflict in 2008-09 and there are new arrivals every day, he said.

"Conditions are increasingly dire in the shelters," he said. "There is no water for hygiene, very few showers, and latrines are totally inadequate. Disease outbreak is beginning with skin infections, scabies and others."

Krahenbuhl said UNRWA is concerned at reports of new instructions from the Israeli military to evacuate the Zeitoun area of Gaza City.

"I believe the population is facing a precipice," he said. "I appeal to the international community to take the steps necessary to address this extreme situation."

Krahenbuhl warned that if further large-scale displacements of people occur in Gaza, Israel as the occupying power "will have to assume direct responsibility to assist these people."

Amos stressed that the parties to the conflict have "an absolute obligation" to protect civilians from direct or indiscriminate attacks.

She demanded that Israel, Hamas and other militant groups be held accountable for meeting international human rights and humanitarian standards, "not the standards of the other party."

Amos stressed that the fighting, now in its 24th day, is making the delivery of aid difficult, noting that 80 percent of the population relied on U.N. assistance even before the conflict.

"Until a longer-term cease-fire is agreed, we need more humanitarian pauses to enable us to reach those in need," she said. "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."

Both Amos and Krahenbuhl called for an end to the violence and the root causes of the conflict to be addressed.

"A cease-fire, while immediately required, is not enough," Krahenbuhl said. "Notwithstanding Israel's legitimate security concerns, the illegal blockade of Gaza must be lifted."

He warned that Gaza will become "unlivable" for its 1.8 million inhabitants in a few years unless urgent steps are taken by the international community to enable the development of Gaza and ensure security in the region.