More than 60 churchgoers were also wounded in the attack, which is reported to be the first in the Syrian capital since rebel groups ousted former president Bashar al-Assad in December, ending more than a decade of civil war.

A gunman opened fire inside the Greek Orthodox St. Elias Church in the Dweila neighbourhood before detonating an explosive vest, according to media reports.

Photos and video from inside the church showed a heavily damaged altar and pews covered in broken glass.

UN chief demands accountability

UN Secretary-General António Guterres strongly condemned the attack, expressing his deepest condolences to the families of those killed and wishing a swift recovery to the injured.

“All perpetrators of terrorism must be held accountable,” Stéphane Dujarric, his spokesperson, said on Monday.

Mr. Guterres noted that the Syrian interim authorities had attributed the attack to the terrorist group, ISIL – also known as Da’esh – based on preliminary investigations, and he called for a thorough and impartial probe.

“The Secretary-General reaffirms the commitment of the United Nations to supporting the Syrian people in their pursuit of peace, dignity, and justice,” Mr. Dujarric added.

Call for justice

UN Special Envoy for Syria Geir Pedersen echoed the condemnation, denouncing the bombing “in the strongest possible terms.”

He urged authorities to investigate the attack and ensure accountability.

He also called for unity in rejecting terrorism, extremism, incitement, and the targeting of any community in Syria, which has been a patchwork of different faiths throughout its history.

No place for extremism

Adam Abdelmoula, the UN Resident and Humanitarian Coordinator in Syria, described the incident as a “deliberate attack on a place of worship” and stressed that it had targeted civilians, including women and children, gathered in prayer.

“There is no room for violence and extremism,” he said, urging solidarity as Syria moves toward recovery and reconciliation.

Mr. Abdelmoula reiterated the UN’s continued support for the Syrian people and called for all possible steps to be taken to protect civilians, prevent future attacks, and bring those responsible to justice.