A bomb ripped through Cairo’s Coptic cathedral complex during Sunday Mass, killing at least 25 people and injuring 49, and delivering the bloodiest attack on Egypt’s Christian minority in recent years, according to Egyptian officials and Christian community leaders.

The explosion unfolded inside St. Mark’s Coptic Orthodox Cathedral at the 100-year-old Botrosiya Church, also known as the Church of St. Peter and St. Paul, shortly after the 200 or so worshipers had stopped reading Bible verses and the priest was getting to ready to start his sermon, witnesses said.

About 9:45 a.m., “everything turned black suddenly,” Qelliny Farag said.

As of Sunday evening, there had been no claims of responsibility. But suspicion immediately fell on Islamist extremists, including Egypt’s Islamic State branch, who have staged numerous attacks across the country this year targeting soldiers, police and government officials. Sunday’s carnage came less than 48 hours after a bomb killed six police officers and injured an additional three on a road leading to Egypt’s famed Great Pyramids complex.

The bombing came on a public holiday here, commemorating the birthday of the prophet Muhammad.

Read more from The Washington Post.

Featured image courtesy of Al Jazeera.