GAZA CITY: Israel vowed Thursday it would not pull troops out of Gaza until they finish destroying a network of cross-border tunnels, despite sharp United Nations criticism over the Palestinian death toll.

Speaking at a special cabinet meeting in Tel Aviv, Prime Minister Benjamin Netanyahu said he would not accept any ceasefire that did not allow troops to continue destroying tunnels used by militants to attack Israel.

“Until now, we have destroyed dozens of terror tunnels and we are determined to finish this mission -- with or without a ceasefire,” he said at the start of the meeting.

“So I will not accept any (truce) proposal that does not allow the (military) to complete this work for the security of Israel's citizens. “

His remarks came after the army confirmed mobilising another 16,000 reservists, hiking the total number called up to 86,000. Israel does not say how many troops are currently fighting inside the Gaza Strip.

Washington also said it had agreed to restock Israel's dwindling munitions supplies, despite increasing international concern over the death toll in Gaza, where 1,397 people have been killed in 24 days of violence.

UN figures indicate two-thirds of the victims were civilians, nearly half of whom were women and children.

The top UN refugee official in Gaza told the Security Council on Thursday that his UNRWA Palestinian refugee agency was stretched to breaking point by the massive humanitarian fallout from the fighting.

“I believe the population is facing a precipice and appeal to the international community to take the steps necessary to address this extreme situation,” Pierre Krdhenb|hl said.

Following the shelling of a UN school in northern Gaza on Wednesday which killed 16, UN human rights chief Navi Pillay slammed Israel for attacking homes, schools and hospitals, accusing it of “deliberate defiance” of international law.

“None of this appears to me to be accidental,” she told reporters.

“There appears to be deliberate defiance of obligations that international law imposes on Israel. “

Tunnel vision

The shelling of the school also drew sharp condemnation from UN chief Ban Ki-moon, who described it as “reprehensible”, as well as from Washington.

But Israel's army suggested the deaths may have been the result of a misfired Palestinian rocket.

“It is not clear if the school was hit by fire from IDF soldiers or from Hamas terrorists,” military spokesman General Moti Almoz told army radio.

Despite rising international calls for a halt to the bloodshed, the Israeli security cabinet decided Wednesday to press on with the Gaza operation just hours after troops had made a significant advance into the narrow enclave.

The offensive began on July 8 with the aim of ending militant rocket fire, but expanded on July 17 with a ground operation aimed at destroying a sophisticated network of cross-border tunnels which Israel has vowed to dismantle.

Major General Sami Turgeman, head of the army's southern command, said Wednesday the army was “just days” away from completing its mission to destroy the tunnels.

Cabinet ministers were briefed on the progress of the operation Thursday in their first meeting since the ground assault began.

Despite a heavy death toll in Gaza on Wednesday when 111 Palestinians were killed, including 17 who died in a strike on a crowded market place and another 16 at the UN school, Washington said it had restocked the army's munitions suplly.

The Pentagon confirmed it had granted a request for ammunition, including some from a stockpile stored by the US military inside Israel for emergency use by the Jewish state.

Rights group Amnesty International had previously urged Washington to halt arms supplies to Israel.

15 hurt in UN school -

There was no let-up Thursday in the bloodshed with at least 15 Palestinians killed, another 13 dying from injuries suffered in earlier attacks and a growing number of bodies pulled from under rubble in areas near Khan Yunis, medics said.

Gaza's emergency services put the toll at 1,397 dead, with more than 8,100 wounded.

And another 15 people sheltering in the UN school in Jabaliya refugee camp that was struck on Wednesday were wounded when Israeli warplanes attacked a mosque next door, medics said.

In Israel, 56 soldiers have died and Hamas rocket fire has killed three civilians, two Israelis and a Thai national.

Despite the loss of life, there appeared to be little Israeli appetite for a truce, with a senior official telling Haaretz newspaper that a ceasefire was not even close.

Nevertheless, an Israeli delegation travelled to Cairo late Wednesday to discuss a possible ceasefire with Egyptian officials, an official at the airport told AFP.

Cairo, a key mediator in previous truce negotiations between Israel and Hamas, was also expected to host a Palestinian delegation later this week.