Before slaughtering 29 Coptic Christians, including children, ISIS militants asked them to renounce Jesus Christ - and killed them when they refused.
Bishop Makarios, the top Coptic Orthodox cleric in Minya, the province where the attack took place, revealed that the Islamic extremists told the Christians they would spare their lives if they converted to Islam.
"They chose death," said Makarios in a television interview aired late Saturday. "We take pride to die while holding on to our faith," he added.
As reported, 10 masked Islamic State militants wearing military uniforms stopped the bus while on its way to the Monastery of Saint Samuel the Confessor. The jihadists reportedly forced the victims walk out, and asked each of them, including the children, whether they were Christians.
When they refused, "Each was killed in cold blood with a gunshot to the head or the throat," said Makarios.
One survivor, a six-year-old boy, said his mother pushed him under her seat and covered him with a bag as the attack began. A young woman speaking from her hospital bed said the assailants ordered the women to surrender their jewelry and money before they opened fire, killing the men first and then some of the women, according to the DailyMail.
Video footage of the attack showed the bus riddled with bullets, with its windows smashed, surrounded by dead bodies covered in black plastic sheets.
ISIS later took responsibility for the murders, making it the fourth attack against Christians in Egypt since December to be claimed by the group. The ongoing attacks have killed more than 100 and injured scores, according to the AP.
Over the weekend, Pope Francis expressed his solidarity with Egypt's Coptic Christians and led thousands of people in prayer Sunday for the victims, who Francis said were killed in "another act of ferocious violence" after having refused to renounce their Christian faith.
Speaking from his studio window over St. Peter's Square, he said: "May the Lord welcome these courageous witnesses, these martyrs, in his peace and convert the hearts of the violent ones."
During a meeting with clergy in the Italian port city of Genoa on Saturday, Francis urged them to pray "for our brothers the Egyptian Copts, who were killed because they did not want to renounce their faith".
"Let's not forget that today there are more Christian martyrs than in ancient times, than in the early day times of the church," he said.
As reported by The Gospel Herald, ISIS earlier this year vowed to step up its attacks against Egypt's Christian minority, who account for about 10 percent of the 92 million population. Copts are the indigenous Christian population of Egypt, who date back to the first decades following the life of Jesus Christ.