RAFAH, Gaza Strip — Israeli troops mistakenly shot three hostages to death Friday in a battle-torn neighborhood of Gaza City, and an Israeli strike killed a Palestinian journalist in the south of the besieged territory, underscoring the ferocity of Israel’s ongoing onslaught.

The deaths were announced as a U.S. envoy tried to persuade the Israelis to scale back their campaign sooner rather than later.

The hostages were killed in the Gaza City area of Shijaiyah, where troops have been engaged in fierce fighting with Hamas militants in recent days. The soldiers mistakenly identified the three Israelis as a threat and opened fire on them, said the army’s chief spokesman, Rear Adm. Daniel Hagari.

He said it was believed that the three had either fled their captors or been abandoned.

“Perhaps in the last few days, or over the past day, we still don’t know all the details, they reached this area,” Hagari said. He said the army expressed “deep sorrow” and was investigating.

Hamas and other militants abducted more than 240 people in the Oct. 7 attack that triggered the war, and the hostages' plight has dominated public discourse in Israel ever since. Their families have led a powerful public campaign calling on the government to do more to bring them home.

Demonstrations in solidarity with the hostages and their families take place nearly every day. Late Friday, hundreds of protesters blocked Tel Aviv’s main highway in a spontaneous demonstration calling for the the hostages' return.

Israeli political and military leaders often say freeing all the hostages is their top aim in the war alongside destroying Hamas.

Still, in seven weeks since ground troops pushed into northern Gaza, they have not rescued any hostages, though they freed one early in the conflict and have found the bodies of several others. Hamas released over 100 in swaps for Palestinian prisoners last month, and more than 130 are believed to still be in captivity.

The three hostages were identified as young men who had been abducted from Israeli communities near the Gaza border — Yotam Haim, 28, Samer Al-Talalka 25, and Alon Shamriz, 26.

Israeli Prime Minister Benjamin Netanyahu called their deaths an “unbearable tragedy” and vowed to continue "with a supreme effort to return all the hostages home safely.”

In southern Gaza, the Al Jazeera television network said an Israeli strike Friday in the city of Khan Younis killed cameraman Samer Abu Daqqa and wounded its chief correspondent in Gaza, Wael Dahdouh. The two were reporting at a school that had been hit by an earlier airstrike when a drone launched a second strike, the network said.

Khan Younis has been the main target of Israel’s ground offensive in the south.

Speaking from a hospital bed, Dahdouh told the network that he managed to walk to an ambulance. But Abu Daqqa lay bleeding in the school and died hours later. An ambulance tried to reach the school to evacuate him but had to turn back because roads were blocked by the rubble of destroyed houses, it said.

Dahdouh, a veteran of covering Israel-Gaza wars whose wife and children were killed by an Israeli strike earlier in the war, was wounded by shrapnel in his right arm.

According to the Committee to Protect Journalists, Abu Daqqa is the 64th journalist to be killed since the conflict erupted: 57 Palestinians, four Israelis and three Lebanese journalists.

Palestinian U.N. Ambassador Riyad Mansour told a General Assembly meeting on the war that Israel “targets those who could document (their) crimes and inform the world, the journalists.”

“We mourn one of those journalists, Samer Abu Daqqa, wounded in an Israeli drone strike and left to bleed to death for six hours while ambulances were prevented from reaching him,” Mansour said.

The Israeli army did not immediately respond to an Associated Press request for comment about Abu Daqqa’s death.

Israel's offensive has flattened much of northern Gaza and driven 80% of Gaza’s population of 2.3 million from their homes. Displaced people have squeezed into shelters mainly in the south in a spiraling humanitarian crisis.

The offensive has killed more than 18,700 Palestinians, according to the Health Ministry in Gaza. Thousands more are missing and feared dead beneath the rubble. The ministry does not differentiate between civilian and combatant deaths. Its latest count did not specify how many were women and minors, but they have consistently made up around two-thirds of the dead in previous tallies.

While battered by the Israeli onslaught, Hamas has continued its attacks. On Friday it fired rockets from Gaza toward central Israel, setting off sirens in Jerusalem for the first time in weeks but causing no injuries. The group's resilience called into question whether Israel can defeat it without wiping out the entire territory.

Israelis remain strongly supportive of the war and see it as necessary to prevent a repeat of the Hamas attack, in which militants killed around 1,200 people, mostly civilians. A total of 116 soldiers have been killed in the ground offensive, which began Oct. 27.

U.S. President Joe Biden’s administration has expressed unease over Israel’s failure to reduce civilian casualties and its plans for the future of Gaza, but the White House continues to offer wholehearted support with weapons shipments and diplomatic backing.

Israeli airstrikes and tank shelling continued Friday, including in Khan Younis and in Rafah, which is one of the shrinking areas of tiny, densely populated Gaza to which Palestinian civilians have been told by Israel to evacuate. Details on many of the strikes could not be confirmed because communications services have been down across Gaza since late Thursday because of fighting.

In meetings with Israeli leaders on Thursday and Friday, U.S. national security adviser Jake Sullivan discussed a timetable for winding down the intense combat phase of the war.

Israeli Defense Minister Yoav Gallant told Sullivan that it would take months to destroy Hamas, but he did not say whether his estimate referred to the current phase of heavy airstrikes and ground battles.

“There is no contradiction between saying the fight is going to take months and also saying that different phases will take place at different times over those months, including the transition from the high-intensity operations to more targeted operations,” Sullivan said Friday.

Sullivan also met with Palestinian President Mahmoud Abbas to discuss Gaza’s postwar future. A senior U.S. official said one idea being floated is to bring back Palestinian security forces driven from their jobs in Gaza by Hamas in its 2007 takeover.

Any role for Palestinian security forces in Gaza is bound to elicit strong opposition from Israel, which seeks to maintain an open-ended security presence there. Netanyahu has said he will not allow a postwar foothold for the Abbas-led Palestinian Authority, which administers parts of the Israeli-occupied West Bank.

The U.S. has said it eventually wants to see the West Bank and Gaza under a “revitalized Palestinian Authority” as a precursor to a Palestinian state — an idea soundly rejected by Netanyahu, who leads a right-wing government that is opposed to Palestinian statehood.

Palestinian officials have said they will consider a postwar role in Gaza only in the context of concrete U.S.-backed steps toward statehood.

In the meeting, Abbas called for an immediate cease-fire and ramped-up aid to Gaza, and emphasized that Gaza is an integral part of the Palestinian state, according to a statement from his office. It made no mention of conversations about postwar scenarios.

The 88-year-old Abbas is deeply unpopular, with a poll published Wednesday indicating close to 90% of Palestinians want him to resign. Meanwhile, Palestinian support for Hamas has tripled in the West Bank, with a small uptick in Gaza, according to the poll. Still, a majority of Palestinians do not back Hamas, according to the survey.