Hamas supporters shout slogans during a protest against the Israeli attacks on Gaza Strip, in the West Bank city of Nablus on Thursday.

AFP/Reuters

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.

Israeli Prime Minister Benjamin Netanyahu, facing international alarm over a rising civilian death toll in Gaza, said on Thursday he would not accept any ceasefire that stopped Israel completing the destruction of militants' infiltration tunnels.

The Israeli military estimated on Wednesday that accomplishing that task, already into its fourth week, would take several more days.

"We are determined to complete this mission, with or without a ceasefire," Netanyahu said in public remarks at a meeting of his full cabinet in Tel Aviv.

"I won’t agree to any proposal that will not enable the Israeli military to finish this important task, for the sake of Israel's security."

Leaving open the option of widening a ground campaign in the Hamas Islamist-dominated Gaza Strip, the Israeli military said it had called up an additional 16,000 reservists. A military source said they would relieve a similar number of reserve soldiers being stood down.

Fighting, however, appeared less ferocious than on previous days this week - more than 100 were killed on Wednesday alone.

Gaza health officials said 19 Palestinians were killed in Israeli assaults on Thursday, which included an air strike on a van in the heart of Gaza City, which killed two people.

The Israeli military said more than 60 rockets were fired from the Palestinian enclave, some deep into Israel. One person was moderately wounded by a Gaza projectile that struck in the southern town of Kiryat Gat.

Hamas said it fired one rocket at Tel Aviv, which the military said was intercepted.

Netanyahu's security cabinet on Wednesday approved continuing operations launched on July 8 in response to a surge of cross-border rocket attacks. Israel also sent a delegation to Egypt, which has been trying, with US blessing, to broker a ceasefire.

Gaza officials say at least 1,410 Palestinians, most of them civilians, have been killed in the battered territory and nearly 7,000 wounded. Fifty-six Israeli soldiers have been killed in Gaza clashes and more than 400 wounded. Three civilians have been killed by Palestinian shelling in Israel.

UN Secretary-General Ban Ki-moon strongly condemned on Wednesday the deaths of at least 15 Palestinians among thousands sheltering at a UN-run school. The UN said its initial assessment was that Israeli artillery shells hit the facility.

The UN' senior human rights official, Navi Pillay, said on Thursday that Israel has attacked homes, schools, hospitals, and UN premises in apparent violation of the Geneva Conventions.

Pillay said Israel's actions seemed to be in "deliberate defiance of obligations that international law imposes".

Related Story