DEIR AL-BALAH, Gaza Strip — Israeli strikes across the Gaza Strip overnight and into Sunday killed at least 22 people, including five children, Palestinian medical officials said, while Gaza’s small Christian community celebrated a pre-Christmas Mass.

Israeli authorities allowed a rare Gaza visit by the leader of the Catholic Church in the Holy Land, Cardinal Pierbattista Pizzaballa, for the Mass while the ever-present buzz of Israeli drones was heard outside.

One of the latest Israeli strikes hit a school housing displaced people in Gaza City and killed at least eight, including three children, according to Gaza’s Health Ministry. Israel’s military said it struck Hamas militants sheltering there.

A strike on a home in the central city of Deir al-Balah late Saturday killed at least eight, including three women and two children, according to Al-Aqsa Martyrs Hospital. Israel’s military said it struck an Islamic Jihad militant. Another six people were killed in separate strikes on Sunday, according to local hospitals.

“The children are still inside the house. We are looking for them. They were sleeping in the living room, five of them together,” said a relative, Noman Abu Samra, as people searched rubble in Deir al-Balah. A window full of children watched.

Israel has carried out daily strikes in Gaza more than 14 months into the war with Hamas. It says it only targets militants, accusing them of hiding among civilians, but the bombings frequently kill women and children.

Israel and Hamas recently appeared to draw closer to a ceasefire agreement that would include the release of Israeli hostages and Palestinian prisoners, but several obstacles remain.

Dozens of worshipers gathered in the Holy Family Church in Gaza City as Pizzaballa and other clergy celebrated Mass. A twinkling Christmas tree was decorated with golden ornaments.

“I want to say, to tell you, that all the world, not only the Christian world, all the world is with you, So the war will finish and we will rebuild,” the cardinal said, urging Palestinians in Gaza to never be afraid.

His visit came as Pope Francis again criticized Israel’s actions in Gaza. Francis said Saturday his envoy had been unable to enter because of Israeli bombing.

“Yesterday children have been bombed. This is cruelty, this is not war,” Francis said during his annual Christmas greetings. On Sunday, he called for a ceasefire.

The pope recently called for an investigation to determine if Israel’s actions in Gaza constitute genocide, a conclusion reached by Amnesty International and Human Rights Watch. The International Court of Justice is investigating genocide allegations brought against Israel by South Africa.

Israel rejects such allegations. It says it is only at war with Hamas. Israel has killed over 45,000 Palestinians in Gaza during the war, according to health officials.