At least 20 people were killed and dozens injured when a suicide bomber blew himself up at the Mar Elias Church in the Dweila neighborhood of Syria's capital Damascus on Sunday, health authorities and security sources said.
The incident marks the first suicide bombing inside Damascus since Bashar al-Assad was toppled by an Islamist-led rebel insurgency in December.
Syria's interior ministry said the suicide bomber was a member of the Islamic State. He entered the church, opened fire and then detonated his explosive vest, the ministry added in a statement.
A security source, speaking on condition of anonymity, said two men were involved in the attack, including the one who blew himself up.
Syria's state news agency cited the health ministry as putting the preliminary casualty toll at nine dead and 13 injured.
A livestream from the site by Syria's civil defence, the White Helmets, showed scenes of destruction from within the church, including a bloodied floor and shattered church pews and masonry.
Syrian President Ahmed al-Sharaa, who led the offensive against Assad before taking over in January for a transitional phase, has repeatedly said he will protect minorities during his tenure.
Turkey's foreign ministry said on Sunday a "treacherous" attack on a church in the Syrian capital of Damascus aimed to disrupt efforts to achieve stability and security in Syria.
"Our belief is full that the Syrian administration and its people will maintain their unity and solidarity, and continue with determination the battle with terrorist organization wanting to create chaos in the country," the ministry said in a statement, adding Turkey would continue supporting Syria.
This is a developing story.