Fears are rising that the conflict could spread to the occupied West Bank, where tensions are soaring among Palestinians angered over deadly Israeli airstrikes in Gaza.
Nearly a week after Israeli tanks and troops poured into Gaza, Israeli military officials say they have made steady gains against Hamas. But the ground operation, which now encircles Gaza City, is entering an acutely perilous phase, with Israelis troops advancing in an urban landscape that is honeycombed with tunnels and home to many Palestinians.
Israeli airstrikes this week on a densely populated neighborhood in northern Gaza that have killed scores of civilians are fueling fears that the war could spread to a second front: the much larger occupied West Bank, where Palestinians have been enraged by the bombardment.
Harrowing images of the dead and wounded are also intensifying international pressure on Israel. On Friday, Secretary of State Antony J. Blinken is expected to press Israel to order “discrete pauses” in the operation to allow more aid to reach civilians and more people to leave the strip, according to United States officials.
One senior Israeli military official said he was confident that the troops would seize control of Gaza, and Israel claims to have killed hundreds of Hamas militants in its assaults. But the official was not sure, with global public opinion turning sharply against Israel, that they would have enough time to root out all of the Hamas forces — a push that Israeli leaders have said could take months.
Publicly, Israeli commanders are claiming steady gains, but offering few details, about their military response to the Hamas attacks of Oct. 7, which left 1,400 soldiers and civilians dead, including women, children and older people and which included torture and abuse.
“Our forces are at the heart of a ground operation in the north of the Gaza Strip,” Lt. Gen. Herzi Halevi, the Israeli military chief of staff, said in a statement on Thursday. “We’re encircling Gaza City.”
Interviews with senior Israeli military officials, who insisted on anonymity to discuss an ongoing offensive, depicted an operation that has achieved considerable progress against a hardened band of Hamas fighters.
Troops are advancing steadily into Gaza City neighborhoods, the officials said, confronting Hamas fighters who emerge from tunnels or other hiding places to try to pick them off. Hamas long used such a tactic in guerrilla clashes with Israeli troops, and it was effective at slowing the advance of soldiers at a time when Israeli commanders acted cautiously to minimize their own casualties.
But this time, the senior Israeli military official said, the enormity of the Oct. 7 attacks has made Israeli commanders less risk-averse about how to engage the enemy. The Israeli military says it has lost about 20 soldiers.
Some Hamas commands have collapsed, two of the officials said, but in other places militants are still fighting vigorously. Many remain hidden in the warren of tunnels, as do the group’s senior leaders.
Israeli officials also said they believed that Hamas’s leadership had been in disarray since the start of the ground operation, when internet, cellular and landline phone services to Gaza were cut.
Still, the operation has yet to achieve one of its key goals: piling enough pressure on Hamas to force it to negotiate the release of more than 200 people abducted during the attacks, or to enable Israel to rescue them in a special military operation.
Hamas’s political leaders are striking a defiant tone. Ghazi Hamad, one of the top leaders, said the group would carry out further attacks on Israel until the nation was annihilated. On Thursday, Hamas released footage that it said showed its fighters firing a grenade launcher at an Israeli tank. Hamas is also demanding fuel deliveries as a condition of releasing hostages, even as the United Nations said the group was stockpiling fuel.
Hamas has confirmed the deaths of some of its middle- and top-ranking commanders in recent assaults, but denied Israeli claims that other top officers had been killed.
After three consecutive days of Israeli airstrikes in the Jabaliya neighborhood of northern Gaza, rescuers were searching for survivors in the rubble of collapsed buildings. Those airstrikes killed and wounded more than 1,000 people, including many children, according to the Hamas controlled Gazan health ministry. As the death tolls rises in these and other assaults, demands for a cease-fire have been growing around the world.
Mr. Blinken, who is meeting with Israeli officials on Friday, is expected to repeat President Biden’s call for a “pause” in the campaign to allow the 240 people held by Hamas to be freed and removed from Gaza. Americans officials described their negotiations with Israelis on these issues as a “work in progress.”
While discussions are ongoing, Israeli forces have cut Gaza in half, having raced across the strip from east to west and reached the Mediterranean Sea on Tuesday. Israel now controls the center of Gaza, a less-settled area with scattered refugee camps. The troops have cut the main north-south roads to Gaza City, depriving Hamas of equipment, vehicles and other reinforcements carried above ground. But many of the tunnels remain intact.
The loss of Gaza’s internet and phone service in the early phase of the operation likely hampered Hamas commanders’ ability to gather intelligence from the field or to communicate with their political leaders in Lebanon. It also helped prevent them from broadcasting images of the assault to the world, which could have raised pressure on Israel to stop.
Yet it deepened the crisis for civilians in Gaza. The death toll from airstrikes has risen to more than 9,000, according to the Gazan health ministry. Hospitals in the strip are running out of fuel and basic supplies, and some doctors say they have had to perform surgery without anesthesia.
The humanitarian disaster is raising tensions in the West Bank, which has already been gripped by a surge of violent attacks by heavily armed Jewish settlers on Palestinians and assaults by Hamas militants on Jews.
Israeli military and intelligence officials said they worried about a broader eruption of violence that could require a major response by a military already heavily deployed in the Gaza operation and in guarding against a potential attack in Israel’s north by the Lebanese-based Hezbollah.
In the past six months, Israeli forces were transferred to reinforce those in the West Bank. But after the Oct. 7 Hamas attack, they were replaced by smaller, less-experienced reserve units, since Israel needed its frontline forces in Gaza.
Military analysts said the Israeli army had enough troops to wage the ground offensive while carrying out regular operations in the West Bank. But it would be overstretched if it were to carry out a parallel offensive in the West Bank, said Yagil Levy, an expert on the Israeli military at the Open University of Israel.
“The army should have calmed down the West Bank,” Professor Levy said. “But they’ve lost much of their control there.”
Since Oct. 7, violence by settlers in the West Bank has displaced more than 800 Palestinians. The United Nations said 120 Palestinians had been killed in clashes with settlers or with the Israeli army, with most dying in clashes with soldiers.
Critics say Israel has exacerbated tensions in the West Bank by halting the transfer of tax and customs revenues to the Palestinian Authority, which controls the territory, after the Hamas attacks. Israel’s finance minister, Bezalel Smotrich, a far-right member of Prime Minister Benjamin Netanyahu’s government, refused to hand over the payments, which Israel collects on behalf of the authority, arguing that the money would go to support Hamas.
Israel’s military intelligence and Shin Bet, its internal security agency, said that the Palestinian Authority was valuable in the fight against Hamas terrorism and that these funds were needed to pay the authority’s workers. Without Palestinian cooperation in counterterrorism, some military officials said, the West Bank could face a third intifada, or uprising, after the deadly Palestinian uprisings of 1987 and 2000.
Mr. Smotrich’s move has opened a bitter split in the cabinet. Israel’s defense minister, Yoav Gallant, demanded that the freeze be lifted, saying in a statement that “the funds should be transferred immediately so that these may be used by the operational mechanism of the Palestinian Authority and by the sectors of the Palestinian Authority that are dealing with the prevention of terrorism.”
Analysts said the Palestinian Authority and its president, Mahmoud Abbas, had been depleted and discredited by their schism with Hamas, which critics said Mr. Netanyahu had exploited. As a result, they said, the authority now has limited influence over armed militias that roam the West Bank and have been galvanized by the fighting in Gaza.
“Even if President Abbas wants to stabilize the situation, I’m not sure the militias agree,” Professor Levy said. “They are tempted to do something to show their sympathy with their brothers in Gaza.”
Mark Landler reported from Jerusalem, and Ronen Bergman from Tel Aviv.