Abu Ubaida, spokesman for Hama’s armed wing, said on Telegram that the group decided to release the detainees "despite the enemy’s refusal to accept them since last Friday and their neglect of the issue of our prisoners."
"We decided to release them for humanitarian and poor health grounds,” he said.
“The enemy refused to receive them last Friday.”
Hamas released two Americans on Friday, nearly two weeks after the group’s fighters abducted them along with dozens of others in southern Israel following an Oct. 7 cross-border assault, killing at least 1,400 people and taking more than 200 hostages.
A Qatar foreign ministry spokesperson on Friday said that the release of U.S. hostages from Gaza came "after many days on continuous communication" with all parties.
Israel pounded hundreds of targets in Gaza from the air on Monday as its soldiers fought Hamas militants during raids into the besieged Palestinian strip as deaths soar and civilians are trapped in harrowing conditions.
Gaza's health ministry said 436 people had been killed in bombardments over the past 24 hours, most in the south of the narrow, densely populated territory, next to which Israeli troops and tanks have massed for a possible ground invasion.
The new fatalities reported bring the number of Palestinians killed in two weeks of strikes to at least 5,087, including 2,055 children, according to casualty figures given by the Hamas health ministry.
The Israeli military said it had struck more than 320 targets in Gaza over 24 hours, including a tunnel housing Hamas fighters, dozens of command and lookout posts, and mortar and anti-tank missile launcher positions.
The Israeli bombardment was triggered by the Oct. 7 assault, the bloodiest episode in a single day since the state of Israel was founded 75 years ago.
With Gaza's 2.3 million people running short of basics, European leaders looked set to follow the United Nations and Arab nations in calling for a "humanitarian pause" in hostilities so aid could reach them.
A U.S. special envoy is negotiating with Israel, Egypt and the United Nations to create a "sustained delivery mechanism" to get aid into Gaza after aid convoys began crossing into the strip from Egypt, State Department spokesperson Matthew Miller said on Monday.
The U.N. said desperate Gazans also lacked places to shelter from the unrelenting bombardment which flattened swathes of the Hamas-ruled enclave.
Russian Foreign Minister Sergei Lavrov stressed the need for a multilateral approach to resolve the conflict and said the United States had not offered any new ideas.
"The more we have such ‘initiatives’ from any one state, the greater in general will be the risks, the danger of the conflict growing," Russia's Interfax news agency quoted him as saying after a regional meeting in Tehran.
Israel's police and the Shin Bet intelligence agency released footage from their interrogations of captured Hamas gunmen who took part in the Oct. 7 rampage of Israeli communities.
In the video clips, one handcuffed Hamas man sitting beside a desk is heard describing the orders they received regarding Israeli civilians - to kill the men and bring the women, children and elderly as hostages.
Another, with an injury on his face, said they were told their prize for bringing captives would be a new home and $10,000.
Fighting inside Gaza
Israel said its armed forces' incursions overnight were partly intended to gather intelligence, with the whereabouts of the hostages unknown, and had helped improve its military readiness.
"These raids are raids that kill squads of terrorists who are preparing for our next stage in the war. These are raids that go deep," military spokesperson Daniel Hagari said.
Hamas's armed wing, the Izz el-Deen al-Qassam Brigades, said its fighters engaged with an Israeli force that infiltrated southern Gaza, destroying two bulldozers and a tank and forcing the raiders to withdraw.
Israel made no comment on the incident.
The Al-Qassam Brigades also said they were firing missiles at the southern Israeli towns of Ashkelon and Mavki'im. Warning sirens sounded on the Israeli side.
The Israeli military, the Middle East's most powerful, faces a group that has built up a large arsenal with Iran's help, fighting in a crowded urban setting and using a vast tunnel network.
The U.N. office for the humanitarian coordination (OCHA) said about 1.4 million of Gaza's population — more than half — were now internally displaced, with many seeking refuge in overcrowded U.N. emergency shelters.
Israel has ordered Gaza residents to evacuate the north. But many who had fled appeared to be returning north due to increased bombardments in the south and lack of shelter.
"They told us to evacuate your place and go to Khan Younis because it is safe ... They betrayed us and bombed us," said 18-year-old Dima Al-Lamdani who lost her parents, seven siblings and four members of her uncle's family in an air strike after the family moved south, according to Reuters reporting.
The conflict meanwhile was escalating beyond Gaza.
Early on Monday, Israeli warplanes also struck two Hezbollah cells in Lebanon that were planning to launch missiles and rockets towards Israel, the Israeli military said. Israel also hit a Hezbollah compound and an observation post.
In the Israeli-occupied West Bank, two Palestinians were killed at the Jalazone refugee camp near Ramallah, the Palestinian Authority health ministry said.
Residents told Reuters that Israeli forces raided the camp and made many arrests as they clashed with gunmen and some youths who threw stones. The Israeli military said 15 suspects were captured, 10 of them Hamas operatives.
A third convoy of 20 aid trucks entered Gaza from Egypt on Monday. The U.N. said aid arriving so far was just 4% of the daily average before the hostilities.
In Brussels, European Union leaders meeting later this week will call for a ceasefire to allow aid to flow safely, according to draft conclusions seen by Reuters. They said they backed a similar call from U.N. Secretary-General Antonio Guterres, who visited Rafah last week. Arab nations also want a truce.