A blast went off on Thursday at a building located on the campus of the historic St. Porphyrius Greek Orthodox Church in Gaza City, a place where scores of Palestinian families had been sheltering from Israeli air strikes.

Some 500 Muslims and Christians were staying on the church grounds following the Oct. 7 attack by Hamas on Israel. The surprise terror attack — where some 1,300 Jews were slaughtered and another 200 taken hostage — has led to two weeks of Israeli air strikes on Gaza.

The attack came days after an explosion at Al-Ahli Arab Hospital, which Palestinian officials said had claimed the lives of up to 300 people, sparked a blame game between Israel, Hamas and the United States.

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Both Israeli officials and U.S. intelligence said the Anglican-run hospital had been struck by an errant Palestinian missile.

Religion Unplugged reported on Oct. 10 that contrary to some reports at the time, the historic Church of Saint Porphyrius — built in the 12th century — had not been destroyed in the bombings. This time, however, Israeli missiles targeted an area near the historic church.

The extent of the damage to the church was not immediately clear, but Palestinian officials said 18 people — eight of whom were children — were killed in the explosion and scores of others injured.

Israeli Defense Forces said on Friday that a strike targeting a Hamas control center “damaged the wall of a church in the area.”

The Palestinian Ministry of Interior in the Gaza Strip called this latest strike a “new massacre.”

In a statement, the Orthodox patriarch in Jerusalem said it “emphasizes that targeting churches and their institutions, along with the shelters they provide to protect innocent citizens, especially children and women who have lost their homes due to Israeli airstrikes on residential areas over the past thirteen days, constitutes a war crime that cannot be ignored.”

Overall, Palestinian officials said the death toll since the start of the war reached 3,859, while another 13,500 people have been injured. Israeli military officials warned this week of a pending ground assault.

Located in the Zaytun Quarter of the Old City of Gaza, St. Porphyrius is named after the fifth-century bishop of Gaza. His tomb is situated in the northeastern corner of the church. It is the oldest active church in the city.

Porphyrius, who lived between the years 347 and 420, was known for Christianizing the then-pagan Gaza City.

The Church of St. Porphyrius has a rectangular shape and features a half-domed roof. The church consists of a single aisle and features three entrances. The western door has a portico with three marble columns, the bases of which date from the Crusades.

In 2014, around 2,000 Palestinian Muslims fleeing Israeli bombings had taken shelter in the church. During the bombings, families slept in the corridors and rooms of the church and adjoining buildings, where they were given shelter, meals and medical care.

Gaza’s Christian community mostly lives within the city, especially in areas neighboring the Church of St. Porphyrius, Holy Family Catholic Parish on Zeitoun Street and the Gaza Baptist Church.

As of last year, there were approximately 1,100 Christians in the Gaza Strip. The area’s population of 1.91 million is largely Muslim.

Clemente Lisi is the executive editor at Religion Unplugged. He is the author of “The FIFA World Cup: A History of the Planet’s Biggest Sporting Event” and previously served as deputy head of news at the New York Daily News and a longtime reporter at The New York Post. Follow him on Twitter @ClementeLisi.