Two masked assailants attacked a Roman Catholic church in Istanbul during a Sunday Mass, killing one person, Turkish officials said, writes The Washington Post.

The armed assailants attacked the Santa Maria Church in the Sariyer district at 11:40 a.m., Interior Minister Ali Yerlikaya said in a statement on the X platform. He didn’t specify what kind of weapons were used or whether anyone was wounded.

Turkish authorities didn’t formally identify the victim, but local media said the person killed had the initials C.T. and was 52 years old.

Hours later, Yerlikaya announced that two men he described as members of the Islamic State extremist movement had been arrested as the suspected attackers. One of the supects is from Tajikistan and the other from Russia, he said at a news conference just after midnight.

Yerlikaya said police had raided 30 locations and detained a total of 47 people as part of the investigation into the attack.

“We will never tolerate those who try to disrupt the peace of our country — terrorists, their collaborators, both national and international criminal groups, and those who aim at our unity and solidarity”, Yerlikaya said.

A short video circulating on social media apparently shows 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 flee.

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