DEIR AL-BALAH, Gaza Strip — Israeli strikes across Gaza killed 28 people overnight and into Sunday, including young quadruplets, local health officials said, as U.S. Secretary of State Antony Blinken headed to the region to try to seal a cease-fire deal after months of negotiations.

The U.S. and fellow mediators Egypt and Qatar said they were closing in on a deal after two days of talks in Doha, with American and Israeli officials expressing cautious optimism. But Hamas has signaled resistance to what it says are new demands by Israel, and the long-running talks have repeatedly stalled.

The evolving proposal calls for a three-phase process in which Hamas would release all hostages abducted during its Oct. 7 attack, which triggered the deadliest war ever fought between Israelis and Palestinians. In exchange, Israel would withdraw its forces from Gaza and release Palestinian prisoners.

The mediators hope to end a war that has killed over 40,000 Palestinians, according to local health authorities, displaced the vast majority of the territory’s 2.3 million residents and caused a humanitarian catastrophe. Experts have warned of famine and the outbreak of diseases like polio.

“It is as if we live a primitive life,” said Sanaa Akela, a displaced Palestinian now in the central town of Deir al-Balah, where sewage flooded some streets.

Hamas-led militants killed some 1,200 people, mostly civilians, in the Oct. 7 attack and abducted around 250. Of those, some 110 are still believed to be inside Gaza, with Israeli authorities saying around a third are deceased. More than 100 hostages were released in November during a weeklong cease-fire.

The latest Israeli bombardment included a strike early Sunday on a home in the central town of Deir al-Balah that killed a woman and her six children, according to the Al-Aqsa Martyrs Hospital. An Associated Press reporter at the hospital counted the bodies.

Mohammed Awad Khatab, the children’s grandfather, said his daughter, a school teacher, was with her husband and their six children when their house was struck. He said the children ranged in age from 18 months to 15 years, and that four of them were quadruplets. He said the father was hospitalized after the strike.

“The six children have become body parts. They were placed in a single bag,” he told reporters outside the hospital. “What did they do? Did they kill any of the Jews?… Will this provide security to Israel?”

A strike in the northern town of Jabaliya hit two apartments in a residential building, killing two men, a woman and her daughter, according to Gaza’s Health Ministry. Another strike in central Gaza killed four people, according to the Awda Hospital. Late Saturday, a strike near the southern city of Khan Younis killed four people from the same family, including two women, according to Nasser Hospital.

Israel says it only targets militants and blames civilian deaths on Hamas because the militant group conceals fighters, weapons, tunnels and rockets in residential areas. But the monthslong Israeli bombardment has wiped out entire extended families and orphaned thousands of children.

The mediators have spent months trying to halt the fighting, efforts that gained new urgency after the targeted killing of two top militants last month, both attributed to Israel, brought vows of revenge from Iran and the Lebanese Hezbollah, raising fears of an all-out war across the Middle East.

An American official said Friday that mediators were beginning preparations for implementing the latest cease-fire proposal, and Israeli Prime Minister Benjamin Netanyahu’s office expressed “cautious optimism” a deal could be reached.

An Israeli delegation is set to travel to Cairo on Sunday for further talks, and Blinken is expected to meet with Netanyahu on Monday.

Hamas has cast doubt on whether an agreement is near, saying the latest proposal diverged significantly from a previous iteration they had accepted in principle. Hamas has rejected Israel’s demands for a lasting military presence along the Gaza-Egypt border and a line bisecting Gaza where Israeli forces would search Palestinians returning to their homes. Israel says both are needed to prevent militants from rearming and returning to the north.

Israel showed flexibility on retreating from the border corridor, and a meeting between Egyptian and Israeli military officials was scheduled for next week to agree on a withdrawal mechanism, according to two Egyptian officials, who spoke on condition of anonymity because they were not authorized to discuss the private negotiations.

In the Israeli-occupied West Bank, which has seen a surge of violence since the start of the war in Gaza, gunmen marched in a funeral procession for two Hamas commanders killed in an Israeli airstrike in Jenin the day before.