Gaza is becoming a “graveyard for children”, UN Secretary General Antonio Guterres says, amplifying demands for a ceasefire in the enclave, where Palestinian health authorities say the death toll from Israeli strikes has exceeded 10,000.

Both Israel and the Hamas militants who control Gaza have rebuffed mounting international pressure for a ceasefire. 

Israel says hostages taken by Hamas during its rampage in southern Israel on October 7 should be released first; Hamas says it will not free them or stop fighting while Gaza is under assault.

“Ground operations by the Israel Defence Forces and continued bombardment are hitting civilians, hospitals, refugee camps, mosques, churches and UN facilities, including shelters. No one is safe,” Guterres told reporters on Monday.

“At the same time, Hamas and other militants use civilians as human shields and continue to launch rockets indiscriminately towards Israel,” he said, calling for an immediate and unconditional release of all hostages.

Israel said 31 soldiers had been killed since it began expanded ground operations in Gaza on October 27 and reiterated that Hamas was hiding with civilians and at hospitals.

Hamas said the idea that Hamas was based in hospitals was a “false narrative that the UN should verify.

A Reuters journalist in Gaza said Israel’s overnight bombardment by air, ground and sea was one of its most intense since the October 7 attack in which Hamas killed 1400 people in Israel and seized more than 240 hostages.

The health ministry in the Hamas-controlled enclave said at least 10,022 people in Gaza have since been killed, including 4104 children.

“Gaza is becoming a graveyard for children. Hundreds of girls and boys are reportedly being killed or injured every day,” Guterres said.

International organisations have said hospitals cannot cope with the wounded and food and clean water are running out with aid deliveries nowhere near enough.

Guterres said 89 people working with the UN Palestinian refugee agency (UNRWA) were among the dead. 

UNRWA said five colleagues had been killed in the past 24 hours alone.

“We need an immediate humanitarian ceasefire. It’s been 30 days. Enough is enough. This must stop now,” an earlier statement by 18 UN organisations said.

The United States is pushing hard to arrange pauses in the conflict to allow in aid rather than a full ceasefire, arguing, like Israel, that Hamas militants would just take advantage.

US President Joe Biden discussed such pauses and possible hostage releases in a phone call with President Benjamin Netanyahu on Monday, reiterating his support for Israel while emphasising that it must protect civilians, the White House said.

The Israeli military said its forces had taken a militant compound and were poised to attack Hamas fighters hiding in underground tunnels and bunkers in the northern Gaza Strip, having isolated the area with troops and tanks. 

The armed wing of Hamas, the Al-Qassam brigades, said it had damaged 27 Israeli military vehicles in 48 hours and inflicted significant losses in direct engagements with Israeli troops.

The health ministry in Gaza said dozens of people were killed by Israeli air strikes in the north and south, including on Gaza City’s Rantissi cancer hospital, where eight people were killed, and a building belonging to Gaza’s largest hospital, Al Shifa, killing one. 

Israel’s military said it was looking into the Rantissi report and denied striking Al Shifa.

The International Committee of the Red Cross said it had escorted a four-ambulance convoy of patients from Gaza City to the Rafah border crossing with Egypt. 

Evacuations had been suspended since an Israeli strike on an ambulance on Friday, but three Egyptian security sources said dozens of foreign passport holders also left on Monday.

US Secretary of State Antony Blinken has toured the region to try to prevent the conflict escalating and plan a secure future for Israelis and Palestinians as well as get in more aid.

“I think we’ll see in the days ahead that assistance can expand in significant ways,” Blinken said in Turkey.

He visited the Israeli-occupied West Bank on Sunday to show support for Palestinians there and in Gaza and held talks in Israel as well as in neighbouring Jordan with Arab leaders.