Israeli strikes across the Gaza Strip overnight and into Sunday killed at least 20 people, including five children, Palestinian medical officials said. Israeli authorities meanwhile allowed Cardinal Pierbattista Pizzaballa, the leader of the Catholic Church in the Holy Land, to enter Gaza and celebrate a pre-Christmas Mass with members of the territory's small Christian community. A strike on a school housing displaced people in Gaza City killed at least eight people, including three children, according to Gaza's Health Ministry. The Civil Defense, first responders affiliated with the Hamas-run government, had earlier said four children were among those killed. The Israeli military said it carried out a precise strike on Hamas militants sheltering there. A strike on a home in the central city of Deir al-Balah late Saturday killed at least eight people, including three women and two children, according to Al-Aqsa Martyrs Hospital, which received the bodies. A man and his wife were .