Istanbul Turkey
The attack happened at the Santa Maria church in the Sariyer district of Istanbul on city's the European side OZAN KOSE/AFP News

The UK Foreign Office has issued an urgent new advisory for Turkey after a fatal attack took place at a Catholic church in Istanbul on Sunday (Jan. 28).

The incident happened during the Sunday mass at around 11:40 AM local time (08:40 GMT), where two gunmen attacked The Church of Santa Maria, leaving a man dead.

Turkey's President Recep Tayyip Erdogan expressed condolences over the attack and said that "necessary steps" were being taken to hunt down the killers, who he anticipated would be found "within 24 hours".

Later on, Turkey's interior minister Ali Yerlikaya said on social platform X, formerly Twitter: "The two murder suspects have been captured," without giving any details on the motive behind the attack.

The Islamic State group later on claimed responsibility for the attack at the historical 19th-century church, located close to a quaint fish market along the European side of the Bosphorus. The IS said that it was in response to a call by the group's leaders to target Jews and Christians.

"On the morning of 28 January 2024, an incident occurred at the Santa Maria Church in the district of Sariyer in Istanbul. We advise all British Nationals in the area to follow the advice of the Turkish authorities. British Nationals in the region should remain vigilant," read the Foreign, Commonwealth and Development Office (FCDO) advisory.

As per reports in the media, the CCTV released by Turkish media has shown the moment of the attack. Worshippers were on their feet, facing the altar when two gunmen came into the back of the church. The attackers appeared to be following a man who had just come in. After he was shot and fatally wounded, the gunmen calmly left.

The Church of Santa Maria is known for its high walls and solemn ambience and now, the streets around it have been closed off by police.

The Pope, meanwhile, also offered his support, expressing his "closeness to the community of the Santa Maria church" at the end of his weekly prayer at the Vatican.

The Islamic State group has carried out numerous attacks across Turkey, including on a nightclub in Istanbul on January 1, 2017, in which 39 people were killed.

Interior Minister Ali Yerlikaya recently claimed that Turkish authorities had detained 2,086 people suspected of ties to the Islamic State group during 1,046 operations since June 2023, and that 529 people had been arrested.