JERUSALEM — Israeli infantry and armored forces invaded the Gaza Strip on Thursday night, escalating an offensive against the Islamist militant group Hamas after efforts to broker a cease-fire failed.
The ground operation raised the prospect of heavier civilian casualties in densely populated Gaza as Israeli forces moved in under cover of a fierce artillery barrage and faced possible urban combat with Islamist militants.
More than 240 Palestinians have been killed and more than 1,800 injured, according to the Gaza health ministry, since Israel launched a bombardment campaign across the Gaza Strip last week in response to rocket attacks from the Hamas-controlled coastal enclave. According to the United Nations, nearly 80 percent of the casualties have been civilians.
In announcing the ground operation, Brig. Gen. Motti Almoz, the chief army spokesman, warned Gaza residents to evacuate areas where fighting was likely.
“Large ground forces, with massive support from the air-force, naval forces and with broad intelligence support are now taking control of objectives in the Gaza Strip, acting against tunnels, acting against infrastructure and terror operatives,” Almoz said. “I ask the residents of the Gaza Strip to evacuate the areas where the Israel Defense Forces are operating. The IDF is operating there with very great force.”
Hamas remained defiant. Hamas spokesman Fawzi Barhoum warned that Israel “will pay dearly” for the ground assault. “Hamas is ready for a confrontation,” he said. As the ground operation got underway, militants in Gaza fired a volley of rockets at the Tel Aviv area, but no casualties were reported. Only one Israeli has died since the campaign began July 8.
Signaling that it was prepared to commit more troops to the ground effort, the Israeli army said it would call up an additional 18,000 reserve soldiers to free regular troops for the Gaza campaign.
The ground push came at a propitious diplomatic moment for Israel, after it had accepted and Hamas rejected an Egyptian cease-fire plan that failed to take hold on Tuesday. Hamas said it was not consulted in advance about the plan, and could not agree to terms dictated to it by the Egyptians.
The Obama administration had pressed Israeli Prime Minister Benjamin Netanyahu not to escalate the Israeli offensive, and on Thursday it urged him to do more to prevent civilian casualties in Gaza. But Hamas’ rejection of the cease-fire plan and continued rocket fire seemed to strengthen the Israeli government’s perception that it had diplomatic leeway to take its military campaign to a new level.
Egypt blamed Hamas for the escalation.
“Had Hamas accepted the Egyptian proposal, it could have saved the lives of at least 40 Palestinians,” Egyptian Foreign Minister Sameh Shoukri was quoted as saying by the state news agency MENA.
Egyptian President Abdel-Fattah el-Sissi has taken a hostile stance toward Hamas and its parent group, the Muslim Brotherhood, which has been designated a terrorist group by the Egyptian government.
A statement from Netanyahu’s office said that he had authorized a ground operation “to strike at terror tunnels penetrating Israel from the Gaza Strip.”
“The prime minister and defense minister have instructed the army to be prepared for broadening the ground operation,” the statement said.
Earlier Thursday, the army said it had foiled an infiltration attempt by 13 Hamas militants through a tunnel dug into southern Israel, striking them from the air after they emerged into Israeli territory.
Thursday’s developments were a reminder of the difficulties of resolving the current fighting. Intense diplomatic contacts to arrange a cease-fire continued in Cairo, but despite initial reports of an approaching agreement, there was no breakthrough toward achieving a deal.
Hamas has insisted that any cease-fire plan include the lifting of Egyptian and Israeli border closures imposed on Gaza, particularly the opening of the Rafah border crossing to Egypt for passage of people and goods.
It has also demanded that Israel release former prisoners it rearrested in the West Bank last month during a crackdown on Hamas that followed the abduction and killing of three Israeli teenagers in the territory. Israel blamed Hamas for the kidnapping, but the group has not claimed responsibility for it.
The ground operation came hours after Israel and Hamas had observed a “humanitarian pause” in hostilities requested by the United Nations to allow Gaza residents to stock up on supplies and seek medical care.
Many ventured onto the streets for the first time in days, taking advantage of the lull to withdraw money at banks and buy food at produce stalls.
After the fighting resumed, Israel said it shot down a Hamas drone sent into Israeli airspace, hitting it with a Patriot missile near the southern coastal city of Ashkelon.
Efforts to mediate a comprehensive cease-fire have been hampered by differences between Israel and Hamas over who would be an acceptable intermediary.
Hamas has been cool to mediation by Egypt because of el-Sissi’s tough stance toward the Islamist group. It prefers either Qatar or Turkey as a go-between, both of which are less acceptable to Israel, and were blamed by Egypt for the breakdown of it truce efforts.
A senior Israeli official said that a Qatari cease-fire initiative was “not on the table,” and that Israel wanted to see Palestinian Authority President Mahmoud Abbas as part of any agreement.
Among the proposed arrangements for opening the Rafah crossing between Gaza and Egypt is stationing border and customs officers there from the Palestinian Authority, replacing Hamas forces.
Abbas met al-Sissi in Cairo on Thursday, a day after holding talks with Moussa Abu Marzouk, the second-ranking leader of Hamas, and he was scheduled to go on to Turkey.
As civilian deaths have mounted in Gaza, Netanyahu has placed the blame squarely on Hamas, accusing it of using civilians as human shields and storing weapons in residential neighborhoods.
The United Nations Relief and Works Agency, which provides assistance to Palestinian refugees, said Thursday that it had found 20 rockets hidden in one of its vacant schools. It said the incident was the first of its kind in Gaza and a “flagrant violation of the inviolability of its premises under international law.”
Greenberg is a McClatchy special correspondent. Email: email@example.com