GAZA CITY, Palestinian Territories - Israeli forces backed by tanks and warplanes Friday pushed into the edges of Gaza in a major operation to destroy Hamas tunnels that the Palestinian Islamist group warned was doomed to fail.
As Israel's offensive against Gaza entered its 11th day, with the army pounding the coastal strip by air and sea as well as from tanks massed along the border, the Palestinian death toll soared to 260.
Civilians were fleeing areas adjoining the border with Israel, with as many as around 30,000 sheltering in United Nations facilities, a UN official told AFP.
"They were shelling from dusk until the early hours of the morning. We've left the eastern front and we're going to a UN school," Shejaiya resident Bassil Araeer told AFP.
"There's no water at home, no electricity at home, just shelling and fear and terror," he said.
During the overnight violence, an Israeli soldier was killed and a five-month-old baby was among 19 Palestinian dead.
The Jewish state said it was pressing ahead with the operation to destroy a network of tunnels that riddle the Gaza strip, used by Palestinian militants to assemble rockets and stage cross-border attacks.
Army spokesman Major Arye Shalicar told AFP that Israel's goal was "to strike Hamas infrastructure and operatives" in Gaza, including tunnels.
Experts say a ground operation is the only way of reaching targets unattainable from the air, such as the underground network.
Before the offensive began late Thursday, the army said it had foiled an underground raid in which 13 Gaza militants managed to infiltrate southern Israel before being spotted by troops.
Warplanes killed at least one of the attackers, and the rest scampered back to the tunnel.
With the launch of a ground war, the Israeli media stressed that the stakes were now high for the Jewish state.
"There is no guarantee that a ground incursion into Gaza will lead to victory," top-selling daily Yediot Aharonot wrote.
"Ground operations are necessary not only to deal with the tunnel problem, but also to project to the other side that Israel is undeterred from a head-on clash." "As of yesterday, Operation Protective Edge was showing signs of a draw, which is basically an Israeli defeat," it added.
"The ground operation is intended to change the situation."
Assault 'to fail'
But militant rockets continued to fall, with nine striking Israel since midnight (2100 GMT) and nine more shot down.
The Israeli assault followed a brief humanitarian truce and urgent diplomatic appeals that Israel redouble 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, the State Department said.
In a telephone call to Israeli Prime Minister Netanyahu, Kerry stressed "the need to avoid further escalation and to restore the 2012 ceasefire as soon as possible." But the Hamas, the main power in Gaza, said the Israeli 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," exiled Hamas chief Khaled Meshaal said in Doha.
Earlier, a Hamas spokesman in Gaza warned Israel would "pay a high price" for the ground operation and that its militants "ready" for the confrontation".
Palestinian president Mahmud Abbas warned the Israeli operation would only lead to "more bloodshed" and complicate ceasefire efforts.
Meanwhile, Israel approved the call-up of another 18,000 reservists, taking the total number approved to 65,000, the army said.
Shortly before putting boots on the ground, the military began an intensive bombardment of Gaza by air and sea, as well as from tanks massed along the border.
And Egypt lashed out at Hamas on Thursday, saying it could have saved dozens of lives had it accepted a truce brokered by Cairo but it also condemned the "Israeli escalation".
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.
A military spokeswoman told AFP that ground and air forces had attacked at least 36 targets in Gaza since the incursion was launched.
Latest military figures show that 1,164 rockets fired from Gaza hit Israel since July 8 and another 321 were shot down by the Iron Dome air defence system.
Gaza is an impoverished and overpopulated enclave in which 1.6 million Palestinians live, many of them refugees.