JERUSALEM/GAZA – Israel on Tuesday said it has re-established control over the Gaza border, and was girding for the next phase of what it promises to be a crushing campaign against Hamas militants.

Israel pounded the Gaza Strip on Tuesday with the fiercest air strikes in its 75-year conflict with the Palestinians, razing whole districts to dust.

Israel’s latest round of air strikes came after Hamas threatened to execute an Israeli captive every time the country bombs a Palestinian home without warning.

On Monday, the Israeli army also called up an unprecedented 300,000 reservists and imposed a blockade on the Gaza Strip.

Those moves raised fears it has planned a ground assault in response to the most audacious and deadly Hamas attack in decades.

The violence has so far claimed close to 2,000 lives.

It prompted international declarations of support for Israel, street protests in support of Palestinians, and appeals for an end to the fighting and protection of civilians.

Israel’s Embassy in Washington said the death toll from the Hamas attack last Saturday had climbed to more than 1,000 Israelis, with at least 2,600 injured, and dozens taken captive.

Among the Israeli dead were 260 mostly young people gunned down at a desert music festival, where some of the hostages were abducted.

In remarks aired by Israel’s Army Radio, chief military spokesman Daniel Hagari said there had been no new infiltrations from Gaza since Monday.

In an apparent response to rumours that gunmen used cross-border tunnels, he said the military had no such findings.

Gaza’s Health Ministry on Monday said at least 770 Palestinians had been killed and more than 4,000 were wounded in Israeli air strikes on the blockaded enclave since Saturday’s attacks by Hamas.

Apartment blocks, a mosque and hospitals were among the sites attacked, and the strikes destroyed some roads and houses, according to media reports and eyewitnesses.

Israel also bombed the headquarters of the private Palestinian Telecommunication Company, which could affect landline telephone, Internet and mobile phone services.

The Israeli military said it hit targets in the Gaza Strip from the sea and air, including a weapons depot it said belonged to the Islamic Jihad group, and Hamas targets along Gaza’s coastline.

Hamas spokesman Abu Ubaida issued the threat on Monday to kill Israelis among the dozens held captive after the surprise attack on Saturday morning.

He said Hamas would execute an Israeli captive for every Israeli bombing of a civilian house without warning, and broadcast the execution.

There was no immediate response from the Israeli military to that threat.

Israeli Foreign Minister Eli Cohen said more than 100 people had been taken captive by Hamas during the deadly cross-border incursion over the weekend.

Forced from home

Palestinians reported receiving calls and mobile phone audio messages from Israeli security officers telling them to leave areas mainly in the northern and eastern territories of Gaza, and warning that the army would operate there.

Dozens of people in Gaza City’s Remal neighbourhood fled their homes.

“We took ourselves, children and grandchildren and daughters-in-law and we ran away. I can say that we became refugees. We don’t have safety or security. What’s this life? This is not a life,” said resident Salah Hanouneh, 73.

In Israel’s south, scene of the Hamas attack, Israel’s chief military spokesman said troops had re-established control of communities inside Israel that had been overrun.

But he said isolated clashes continued as some gunmen remained active.

The announcement that 300,000 reservists had been activated in just two days added to speculation that Israel could be contemplating a ground assault of Gaza, a territory it abandoned nearly two decades ago.

“We have never drafted so many reservists on such a scale,” Rear Admiral Hagari said. “We are going on the offensive.”

Washington – which provides Israel with US$3.8 billion (S$5.2 billion) in military assistance each year – said it was sending in fresh supplies of air defences, munitions and other security assistance to Israel.

The United States’ top general warned Iran not to get involved in the crisis and said he did not want the conflict to broaden.

Iran makes no secret of its backing for Hamas and has applauded the weekend attack while denying any involvement.

“We want to send a pretty strong message. We do not want this to broaden and the idea is for Iran to get that message loud and clear,” General Charles Brown, chairman of the Joint Chiefs of Staff, told reporters travelling with him to Brussels.

US Secretary of State Antony Blinken discussed US support for Israel in a call with Mr Cohen, the State Department said in a statement early on Tuesday.

Mr Blinken “reaffirmed our efforts to secure the immediate release of all hostages”, the statement said.

Governments including Italy, Thailand and Ukraine reported that their citizens had perished in the Hamas attacks.

In Washington, President Joe Biden announced that at least 11 Americans had been killed, and it was likely US citizens were among those held hostage.

As Israel conducted intense retaliatory strikes on Gaza, Defence Minister Yoav Gallant drew international condemnation by announcing a tightened blockade to prevent food and fuel from reaching the strip, home to 2.3 million people.

Hamas-affiliated media said at least 20 people had been killed in Israeli strikes on houses in the Gaza Strip late on Monday.

Palestinian media also reported that an Israeli air strike on a building in Gaza City had killed two Palestinian journalists and seriously wounded a third.

Reuters was not immediately able to confirm the reports. The Israeli military had no immediate comment.

International response

United Nations Secretary-General Antonio Guterres said some 137,000 people were taking shelter with UNRWA, the UN agency that provides essential services to Palestinians.

The British, French, German, Italian and US governments issued a joint statement recognising the “legitimate aspirations” of the Palestinian people, and supporting equal measures of justice and freedom for Israelis and Palestinians alike.

They also said they would remain “united and coordinated” to ensure Israel can defend itself.

Egyptian President Abdel Fattah al-Sisi and his Turkish counterpart Recep Tayyip Erdogan called on Hamas and Israel to immediately end violence and protect civilians, the Egyptian presidency said.

Qatari mediators held urgent calls to try to negotiate freedom for Israeli women and children seized by Hamas in exchange for the release of 36 Palestinian women and children from Israeli prisons.

The prospect that fighting could spread alarmed the region and world.

Lebanese armed group Hezbollah fired rockets into northern Israel in response to at least three of its members being killed in Israeli shelling of Lebanon.

Israel said one of its deputy commanders was killed in an earlier cross-border raid from Lebanon. REUTERS