Pope Francis lamented the war in the Holy Land where Palestinian health officials said airstrikes killed at least 78 people on Christmas Eve in one of the Gaza Strip's deadliest nights in Israel's 11-week-old battle on the besieged Palestinian territory.
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 airstrike targeting Maghazi in central Gaza, health ministry spokesperson Ashraf Al-Qudra said, adding that many were women and children.
Israeli forces said it was reviewing the report of a Maghazi incident and claimed it 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 (PRCS) published footage of the wounded being transported to hospitals. It said Israeli warplanes were bombing main roads between central Gaza, hindering the passage of ambulances and emergency vehicles.
Medics said a separate Israeli airstrike 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.
"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," Pope Francis said, presiding at Christmas Eve Mass in St. Peter's Basilica in Rome.
Palestinian Christians earlier held a Christmas vigil in Bethlehem with candle-lit 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.
Israel has besieged the Gaza Strip and laid much of it to waste, with more than 20,400 people confirmed killed, according to Palestinian authorities in Gaza, and thousands more are believed dead under the rubble.
The vast majority of the 2.3 million Gazans have been driven from their homes and the United Nations says conditions are catastrophic.