JERUSALEM — Israeli Prime Minister Benjamin Netanyahu pledged Monday that there would be no letup in the battle against the militant Islamist group Hamas in the Gaza Strip and warned Israelis to be prepared for a long conflict.
Netanyahu made his vow as international pressure grew for Israel to halt its offensive, a strike killed one adult and nine children on a Gaza playground, and a militant mortar attack killed four Israeli soldiers.
“We have to be prepared for a prolonged campaign,” Netanyahu told Israelis, vowing to continue the military operation until Hamas attack tunnels in Gaza were destroyed.
After the deadly mortar strike on an army staging point on Israel’s frontier with Gaza and a foiled infiltration attempt by Hamas gunmen who tunneled under the border, the military warned hundreds of thousands of Palestinians to leave their homes in areas of the northern Gaza Strip in preparation for intensified strikes.
“It is recommended that residents of Gaza move away from places where Hamas is operating,” said Lt. Gen. Benny Gantz, the army chief of staff. “We will get there, and when we do, it will hurt.”
Defense Minister Moshe Yaalon warned that Israel would “not hesitate to broaden” military operations against Hamas. “We will hit them hard until Hamas understands that the current reality is destructive for it and for residents of the Gaza Strip.”
The prospect of renewed escalation of the fighting came as hopes faded for a diplomatic end to the hostilities.
Netanyahu denounced as one-sided a U.N. Security Council statement calling for an immediate and unconditional cease-fire to allow the delivery of humanitarian aid to Gaza. He told U.N. Secretary-General Ban Ki-moon that the non-binding “presidential statement” by the council dealt with “the needs of a murderous terrorist organization that attacks Israeli citizens, and does not address Israel’s security needs,” according to a statement from Netanyahu’s office.
Ban pleaded for an end to the fighting, which has claimed the lives of about 1,100 Palestinians, most of them civilians, according to Gaza health officials. Forty-eight Israeli soldiers and three civilians have died in the conflict.
“In the name of humanity, the violence must stop,” Ban told reporters, adding that the Gaza Strip, where the U.N. says some 200,000 people have been displaced by the fighting, is in “critical condition.”
Ban said that both sides have behaved in an irresponsible, “morally wrong” way by allowing the violence to continue.
“It’s a matter of their political will,” he said. “They have to show their humanity as leaders, both Israeli and Palestinian.”
A strike on a park in the Shati refugee camp in Gaza City killed 10 people Monday, nine of them children, and injured dozens more, medical officials said. The children, some of whom were playing on a swing, were out with their families on the first day of Eid al-Fitr, marking the end of the Muslim holy month of Ramadan.
A spokesman for the Hamas-run Interior Ministry in Gaza said the deaths were caused by an Israeli strike, but the Israeli army said the lethal blast was caused by a misfired rocket, launched by militants, that it had tracked.
The Israeli newspaper Haaretz cited a field worker for the Al-Mezan Center for Human Rights in Gaza as saying that he was told by witnesses that a car carrying militants passed by at the time of the attack and may have been the intended target of an Israeli strike.
A few minutes earlier another strike hit an outpatient clinic at Gaza City’s main hospital, Al-Shifa, leaving several people wounded, according to reports from the scene. Gantz, the Israeli army’s chief of staff, said that aerial monitoring of rocket launches in Gaza showed that the hospital compound had been hit by a misfired rocket.
In southern Israel, mortar rounds struck a military staging area near the Gaza border, killing four soldiers and wounding several others, the army said. A squad of Hamas gunmen that tunneled into Israel near a kibbutz on the border exchanged fire with Israeli soldiers, and one militant was killed, the army said.
Another soldier in the army corps of engineers was killed inside the Gaza Strip when an anti-tank rocket struck a bulldozer he was operating, the army said.
President Barack Obama discussed the situation in Gaza on Monday in a video conference with British Prime Minister David Cameron, French President Francois Hollande, German Chancellor Angela Merkel and Italian Prime Minister Matteo Renzi.
The leaders agreed on the need for “an immediate, unconditional humanitarian cease-fire, noting shared concern about the risk of further escalation and the loss of more innocent life,” the White House said.
Conflicting demands by Hamas and Israel, which have grown as the conflict drags on, have hampered efforts to arrange a truce.
On Monday, Netanyahu insisted that any future agreement on Gaza would have to include measures to prevent the arming of Hamas and to demilitarize the Gaza Strip, ridding it of the group’s stocks of rockets and heavy weapons.
Speaking in Washington, Secretary of State John Kerry appeared to endorse Netanyahu’s demand, saying that “any process to resolve the crisis in Gaza in a lasting and meaningful way must lead to the disarmament of Hamas and all terrorist groups.”
However, in a phone call with Netanyahu on Sunday, Obama appeared to relegate that issue to a later stage, saying it should be part of a future solution to the Israeli-Palestinian conflict.
Kerry was criticized in recent days by Israeli officials unhappy with his latest cease-fire proposals, which they said tilted toward Hamas and its demands for lifting border closures imposed by Israel and Egypt on the Gaza Strip.
The White House staunchly defended Kerry against the criticism on Monday, even as it remained unclear what the administration would do next to resolve the Gaza crisis.
Tony Blinken, Obama’s deputy national security adviser, told reporters that “Israel has no better friend, no stronger defender” than Kerry and that “no one has done more to help Israel achieve a secure and lasting peace. He has been tireless in his efforts and I think that Israel and many countries and friends around the world recognize exactly that.”
Blinken said the proposal criticized in Israel was not a U.S. proposal but a discussion paper based on an original Egyptian cease-fire initiative and aimed at eliciting comment from the Israelis.
“Virtually every element that unidentified sources complained about was in the initial Egyptian proposal and agreed to by Israel 10 days before,” Blinken said. “The bottom line on this is that what was leaked, unfortunately, was I think an effort to misinform, or was just misinformed.”
Israel’s ambassador to the U.S., Ron Dermer, tried to defuse the tensions over Kerry’s role.
“I speak directly for my prime minister here,” he said in a speech to Jewish leaders gathered Monday in Washington. “The criticism of Secretary Kerry for his good-faith efforts to advance a sustainable cease-fire is unwarranted.”
Special correspondent Greenberg reported from Jerusalem, Clark from Washington.