The Islamic State group claims responsibility for the Istanbul church attack that killed one person

ISTANBUL — The Islamic State group has claimed responsibility for an attack on a Roman Catholic church in Istanbul during a Sunday Mass that killed one person.

The extremist group said in a statement late Sunday on Aamaq, the group's media arm, that it “attacked a gathering of Christian unbelievers during their polytheistic ceremony” inside the Santa Maria Church in the Buyukdere neighborhood in Istanbul.

The 52-year-old man who was shot and killed, Tuncer Cihan, "was ... a person who had done nothing wrong. In fact, he wasn’t even Christian, he was Alevi,” the church’s lawyer Avsin Hatipoglu told The Associated Press, adding they would ask authorities to increase security in the area.

Turkey’s Alevi community is one of the country’s largest religious minorities. Alevis identify as Muslims, though their practice is fundamentally different from Islam’s two major branches, Sunni and Shiite.

Interior Minister Ali Yerlikaya said two men he described as members of the Islamic State group had been arrested. One is from Tajikistan and the other from Russia, he said, adding that police raided 30 locations and detained suspects with alleged links to the shooting.

DHA, a private news agency, reported that 51 people were detained during the police raids, including 23 who were sent to holding centers awaiting deportation. It also said the two suspects drove a car brought from Poland to Istanbul a year ago which had been not used until the day of the shooting. The attackers panicked and ran away after the weapon jammed, it said.

Istanbul police didn’t immediately respond to a request for information.

Still reeling from the attack, the clergy of Santa Maria opened their doors to the press on Monday, saying Mass will resume on Thursday. Pews and walls were peppered with bullet holes. A bouquet was left where Cihan was killed.

Sukru Genc, mayor of Sariyer district where the attack took place, told the newspaper Birgun that the gunmen fled when their weapon jammed after firing two rounds.

Genc said people attending Mass included Polish Consul General Witold Lesniak and his family, all unharmed in the attack.

On Jan. 3, 25 suspected Islamic State members were arrested across Turkey and accused of plotting attacks on churches and synagogues, according to the state-run Anadolu Agency.

The Islamic State has not previously targeted places of worship in Turkey but has carried out a string of deadly attacks in the country, including a shooting at an Istanbul nightclub in 2017 that killed 39 people and a 2015 bomb attack in Ankara that killed 109.