A general strike in Israel disrupted banks, public transit, hospitals, stores and the country's main airport as the largest Israeli trade union sought to pressure the government to reach a cease-fire deal with Hamas, days after six more hostages were found dead in Gaza.

Arnon Bar-David, chairman of the trade union Histadrut, said Sunday that reaching a deal to free hostages being held Hamas in Gaza "is the most important thing."

"Until now, I have shown a lot of responsibility, and it hasn't been easy," Bar-David said. "But I feel that we cannot stand idly by. We cannot ignore the cries of our children who are being murdered in the tunnels in Gaza; it is inconceivable. We are in a downward spiral and keep receiving body bags."

The hostages were apparently shot to death by the militants just as troops were zeroing in on their location in Gaza. Israel's foreign ministry said early Monday a forensic examination showed the hostages were killed by gunshots at close range, and within 48-72 hours before the examination.

Monday's strike followed protests Sunday night in which tens of thousands of people demanded Israeli Prime Minister Benjamin Netanyahu agree to a cease-fire.

Thousands of people gathered outside Netanyahu's office in Jerusalem. In Tel Aviv, hostages' relatives marched with coffins to symbolize the death toll.

The protest appeared to be the largest such demonstration in nearly 11 months of war.

Earlier Sunday, Netanyahu vowed to intensify the fight with Hamas after the Israeli military recovered the dead hostages' bodies."

"Those who kill hostages do not want an agreement" for a Gaza cease-fire, Netanyahu said in a statement, telling Hamas leaders, "We will hunt you down, we will catch you and we will settle the score."

Netanyahu also accused Hamas of carrying out a shooting attack earlier Sunday that killed three police officers near the city of Hebron in the Israeli-occupied West Bank. Hamas has not claimed responsibility for the attack but called it a "heroic operation by the resistance."

While the fighting in Gaza and the West Bank remained at the forefront, "humanitarian pauses" were started at several locations in Gaza so that the U.N. agency for Palestinians and the World Health Organization could start vaccinating 640,000 children under the age of 10 over the next several days against the threat of polio.

The disease was recently detected in Gaza for the first time in 25 years.

Hamas militants killed about 1,200 people and took 250 hostage during an October attack on southern Israel. The Israeli counteroffensive has killed nearly 41,000 Palestinians in Gaza, most of them women and children, according to Gaza health officials, while the Israeli military says the death toll includes several thousand Hamas combatants.

Israel says it believes 101 Israeli and foreign hostages remain in Gaza, but about one-third of them is believed to be dead, while the fate of the others is not known.

Senior Hamas officials said that Israel, in its refusal to sign a cease-fire agreement, was to blame for the newest deaths.

"Netanyahu is responsible for the killing of Israeli prisoners," senior Hamas official Sami Abu Zuhri told Reuters. "The Israelis should choose between Netanyahu and the deal."

Hamas has offered to release the hostages in return for an end to the war, the withdrawal of Israeli forces and the release of dozens of Palestinian prisoners, including high-profile militants, jailed by Israel.

The Hostage Families Forum called on Netanyahu to take responsibility and explain what was holding up an agreement.

"They were all murdered in the last few days, after surviving almost 11 months of abuse, torture, and starvation in Hamas captivity. The delay in signing the deal has led to their deaths and those of many other hostages," it said.

Defense Minister Yoav Gallant called on the government to reverse a decision last Thursday to keep Israeli forces in the Philadelphi Corridor along the border with Egypt, a key point of contention in negotiations for a cease-fire in Gaza.

"The Cabinet must gather immediately and reverse the decision made on Thursday," Gallant said in a statement. "We must bring back the hostages that are still being held by Hamas." Gallant and Netanyahu got into a shouting match over the corridor issue, but other security officials sided with Netanyahu.

U.S. President Joe Biden, who has closely followed the fate of the hostages, said the six bodies found in the Gaza tunnel included Israeli American Hersh Goldberg-Polin. Biden said he was "devastated and outraged."

"Hamas leaders will pay for these crimes. And we will keep working around the clock for a deal to secure the release of the remaining hostages," he said in a statement.

Vice President Kamala Harris, the Democratic presidential nominee, said she and her husband, Doug Emhoff, spoke to Goldberg-Polin's parents, Jon and Rachel, to express their condolences.

"My heart breaks for their pain and anguish," Harris said. "I told them: As they mourn this terrible loss, they are not alone. Our nation mourns with them."

Some information for this report was provided by The Associated Press, Reuters and Agence France-Presse.