Palestinian health officials said air strikes killed at least 78 people on Christmas Eve in one of Gaza’s deadliest nights in Israel’s 11-week battle with Hamas.

Israeli strikes that began hours before midnight persisted into Christmas Day on Monday. Local residents and Palestinian media said Israel stepped up air and ground shelling against al-Bureij in central Gaza.

At least 70 people were killed in an Israeli air strike targeting Maghazi in central Gaza, health ministry spokesman Ashraf al-Qidra said, adding that many were women and children.

The Israeli army said it was reviewing the report of a Maghazi incident and was committed to minimising harm to civilians. Hamas denies the Israeli charge that it operates in densely populated areas or uses civilians as human shields.

The Palestinian Red Crescent published footage of the wounded being taken to hospitals. It said Israeli warplanes were bombing main roads between central Gaza, hindering the passage of ambulances and emergency vehicles.

Doctors said a separate Israeli air strike in Khan Younis in southern Gaza killed eight Palestinians.

Clergy cancelled celebrations in Bethlehem, the Israeli-occupied Palestinian West Bank city where tradition has it that Jesus was born in a stable 2,000 years ago.

Palestinian Christians earlier held a Christmas vigil in Bethlehem with candlelit hymns and prayers for peace in Gaza instead of the usual celebrations.

There was no large tree, the usual centrepiece of Bethlehem’s Christmas celebrations. Nativity figurines in churches were placed amid rubble and barbed wire in solidarity with the people of Gaza.

Pope Francis, presiding at Christmas Eve Mass in St Peter’s Basilica in Rome, said: “Tonight, our hearts are in Bethlehem, where the Prince of Peace is once more rejected by the futile logic of war, by the clash of arms that even today prevents him from finding room in the world.”

Since a week-long truce collapsed at the start of the month, fighting has only intensified on the ground, with war spreading from the north of Gaza to the full length of the densely populated enclave.

The Israeli military said 10 of its soldiers had been killed in the past day, following five killed the previous day, its worst two-day losses since early November.

“This is a difficult morning, after a very difficult day of fighting in Gaza,” Prime Minister Benjamin Netanyahu told his cabinet on Sunday. “The war is exacting a very heavy cost from us; however we have no choice (but) to continue to fight.”

In a later video message he said troops would fight on deeper into Gaza until “total victory” over Hamas.

Israel has been under pressure from its closest ally the United States to shift its operations into a lower density phase and reduce civilian deaths.

On Saturday, Israel’s military chief of staff said his forces had largely achieved operational control in the north of Gaza and would expand operations further in the south.

But residents say fighting has only intensified in northern districts.

Diplomatic efforts, mediated by Egypt and Qatar, on a new truce to free remaining hostages held by militants in Gaza have yielded little public progress, although Washington described the talks last week as “very serious.”

Islamic Jihad, a smaller militant group allied to Hamas, said a delegation led by its exiled leader Ziad al-Nakhlala was in Cairo on Sunday. His arrival followed talks attended by Hamas chief Ismail Haniyeh in recent days.