The death toll among Palestinians soared to 260 as the large-scale Israeli offensive entered its 11th day, with the army bombarding Gaza by air and sea as well as from tanks massed along the border.
Israel reported its first combat death since its troops went in, while a five-month-old baby was among the 19 Palestinians reported killed on Friday.
The Jewish state said it was pressing ahead with the operation to destroy a network of tunnels that riddle the Gaza strip, used for assembling rockets and staging cross border attacks.
Before the ground offensive was launched, the army said it had foiled a subterranean raid by Gaza militants into southern Israel.
Thirteen militants emerged from a tunnel under the Gaza border, and were headed towards Sufa kibbutz, a small community just over a kilometre away, when they were spotted, it said.
Warplanes killed at least one of the attackers, and rest ran back to the tunnel.
As the incursion began late Thursday, rockets lit up the sky, and the force of the shelling shook violently a seafront hotel in Gaza City housing scores of journalists.
The assault followed a brief humanitarian truce and urgent diplomatic appeals that Israel redouble its efforts to avoid harm to civilians.
US Secretary of State John Kerry urged Israel to limit collateral damage in Gaza and be "precise" in its ground assault on the enclave.
Kerry emphasised in a telephone call to Israeli Prime Minister Netanyahu "the need to avoid further escalation and to restore the 2012 ceasefire as soon as possible," said the State Department.
Hamas, the movement that controls Gaza, said the ground operation was destined to fail.
"What the occupier Israel failed to achieve through its air and sea raids, it will not be able to achieve with a ground offensive. It is bound to fail," Hamas chief Khaled Meshaal said from his exile in Doha.
A Hamas spokesperson in Gaza earlier said "Israel will pay a high price" for launching the ground operation and that his movement "is ready for the confrontation".
Palestinian president Mahmud Abbas said Israel must stop its ground operation, warning it would lead to "more bloodshed" and complicate efforts to end the conflict in the enclave.
Israel approved the call-up of another 18,000 reservists, taking the total number approved to 65,000 for an operation aimed at protecting Israeli lives and striking "a significant blow to Hamas's terror infrastructure," the army said.
Shortly beforehand, the military began an intensive bombardment of Gaza by air and sea as well as by tanks massed along the border.
Israel launched Operation Protective Edge on July 8 to stamp out rocket fire from Gaza, pounding the coastal enclave from both the air and the sea.
Egypt lashed out at Hamas on Thursday, saying it could have saved dozens of lives had it accepted a truce brokered by Cairo but also condemned the "Israeli escalation".
"Had Hamas accepted the Egyptian proposal, it could have saved the lives of at least 40 Palestinians," said Foreign Minister Sameh Shoukri.
An initial ceasefire proposal which was to begin on Tuesday was accepted by Israel but ignored by Hamas, which continued to fire rockets over the border.
Netanyahu and his defence minister, Moshe Yaalon, instructed the army "to commence ground action to strike at the terrorist tunnels from the Gaza Strip into Israeli territory," the premier's office said.
Army spokesperson Major Arye Shalicar told AFP Israel's goal was "to strike Hamas infrastructure and operatives" in Gaza, including tunnels.
Experts have said a ground operation is the only way of reaching targets unattainable from the air, such as the underground network.
Almoz urged Gaza residents to flee areas where the army was operating, warning the ground campaign would "be extended as much as necessary".
Following appeals by Washington and the United Nations, the military pledged to invest "unprecedented efforts" to limit harm to civilians.
"I regret that despite my repeated urgings, and those of many regional and world leaders together, an already dangerous conflict has now escalated even further," UN chief Ban Ki-moon said, urging Israel to "do far more" to spare Palestinian non-combatants.
On the ground, Palestinian witnesses reported gun battles breaking out east of the southern city of Khan Yunis, with military sources confirming it was one of the areas in which the troops were operating.
A military spokesperson told AFP ground and air forces had attacked at least 36 targets in Gaza since the incursion was launched.
Following the start of the ground operation, 25 rockets fired by Gaza militants hit Israel without causing any casualties, with another 20 intercepted, the army said Friday.
Military figures also show that 1,155 rockets fired from Gaza have hit Israel from July 8 to Friday, and another 312 shot down by the Iron Dome air defence system.
COMMENTS (14)
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@unbelievable: "Hamas turned it down"
Yes, those Hamas people refused to accept the dreadful Israeli brutality. How could they be so uncooperative?
I really hope Malala Yusofzai can come out in support of Palestinian children. These are kids.
@Juror # 8: Dear Juror, The only history I am aware of is that written by the Jews and it appears from their narrative that Moses and his associates settled Palestine illegally by force a few thousand years ago. However, using Jewish demographics it appears that the total population of Israel/Palestine as late as the year 1517 was 5,000 or 1.7 per cent. I hope this helps you?
What a brave army - killing un-armed civilians, woman n children, it's PM n army Generals must received Medals from lady "UN".
@nawal: "occupying palestine" Clearly your history is distorted, ask your self if Israel is occupying Palestine then where were they living when Holy Books calls them children of Israel or Bani Israel??? Do you know what was it called before Romans changed its name to Palestine? This land was called Judea from which we now knows them as Jews. Think about it hot shot.
@Sexton Blake: " original inhabitants", rather being fanatic you should learn some history. Israel are the original inhabitants for centuries.
@Eddied Dnt blame hamas..Offcourse when israeli forces have been occuyping palestine since half a century then palestians also have right to retaliate.. hamas is doing right.. if israel withdraws its forces today frm palestine.. hamas wl do nothing to harm israel
@Hadi: That's rubbish. Egypt proposed a temporary ceasefire and invited both Israel and Hamas to Cairo to negotiate terms for a permanent ceasefire. The proposal was announced publicly to the World and not negotiated with Israel/Hamas or anybody else. Hamas turned it down -- end of story.
it is to be noted that Hamas is a democratically elected government. And all those who are saying Hamas is to blame for not accepting the ceasefire should know that the so called ceasefire was a deal done by israel and egypt on their own terms. Hamas was never invited as a party in the deal. and once it was signed, they offered it to Hamas for signing without addressing their concerns. it is all a sham concocted to portray to the world that Hamas is to blame.
@Eddied: With no army, navy and no means to defend them selves against the oppressors you have the audacity to call them the terrorist. If any one is the terrorist it Israel and IDF. They occupied Palestine land, have been creating illegal settlements against all UN resolutions, illegally taking away their homes and land, killing their children and then expect the oppressed not to retaliate. Such Barbarians they are!!
@Eddied: Nobody invited the Jews. If they don't like it they should get out instead of killing the original inhabitants.
@Eddied: Who will make sure Israel won't kill innocents and displace them to make way for new installments for Jews? Does Israel even care about UN?
The blame for this disaster goes to Hamas, only Hamas and completely Hamas!...the refusal by these terrorists to talk to or even recognize the country of Israel continues to cause pain and suffering to the Palestinian people...until the Palestinians reject these radical terrorist leaders and this insane endless war against the Jews it is the Palestinians who will suffer the most...the violence that Hamas promotes has not worked and will not work to make things better for the people...
Please come to the negotiating table and TALK . I am sure that there is SOME way out .