ISTANBUL — Two masked assailants attacked a Roman Catholic church in Istanbul during a Sunday Mass, killing one person, Turkish officials said.

The armed assailants attacked the Santa Maria Church in the Sariyer district at 3:30 a.m. EST, Interior Minister Ali Yerlikaya said in a statement on X, formerly known as Twitter. He didn’t specify what kind of weapons were used or whether anyone else was wounded.

Yerlikaya condemned the attack and said authorities were working on capturing the assailants. An investigation was opened.

A short video circulating on social media depicts the moment of the attack, with two masked men entering the church and opening fire, with all service-goers hitting the floor. The two men then abruptly leave.

Turkish authorities have instituted a media ban on coverage of the attack.

Istanbul Mayor Ekrem Imamoglu offered his condolences and support for religious minorities in the city, which like Turkey as a whole is primarily Muslim.

“There are no minorities in this city or this country. We are all actual citizens,” he told reporters.

Pope Francis noted the attack in remarks to the public at St. Peter’s Square in Vatican City on Sunday.

“I express my closeness to the community of (the church) in Istanbul, which during the Mass suffered an armed attack with one dead and some wounded,” the pontiff said.

Speaking to the Associated Press, the victim’s nephew identified the man who died as Tuncer Cihan. He noted that the target was the church and not his uncle.

“He was a mentally disabled individual who had no connection to politics or (criminal) organizations. He went there on an invitation and was a victim of fate,” Cagin Cihan said.

The church is run by an Italian order of Franciscan friars. Italian Foreign Minister Antonio Tajani said that his ministry was following the situation along with the Italian Embassy in Turkey’s capital, Ankara, and the consulate in Istanbul.

“I express my condolence and firm condemnation for the vile attack on Santa Maria Church,″ Tajani tweeted. He added “I am certain that the Turkish authorities will arrest those responsible.