April 30, 2017 0632 GMT
In the first attack, a bomb exploded at Saint George Church in the Nile Delta city of Tanta, killing at least 26 people and wounding over 70, officials said, AP reported.
Later, an explosion hit Saint Mark's Cathedral in the coastal city of Alexandria, the historic seat of Christendom in Egypt, killing at least 11 people and wounding 35 just after Pope Tawadros II finished services. His aides later told local media that he had escaped unharmed.
The blasts came at the start of Holy Week leading up to Easter, and just weeks before Pope Francis is due to visit the Arab world’s most populous country.
CBC TV showed footage from inside the church in Tanta, where a large number of people gathered around what appeared to be lifeless, bloody bodies covered with papers. Regional Deputy Health Minister Mohammed Sharshar confirmed the toll.
Across the street, neighbor Susan Mikhail, whose apartment has a clear balcony view of the church and its front yard, said the explosion violently shook her building midmorning, at a time when the church was packed.
Pope Francis decried the bombings, expressing “deep condolences to my brother, Pope Tawadros II, the Coptic Church and all of the dear Egyptian nation.”
Grand Sheikh Ahmed el-Tayeb, head of Egypt's Al-Azhar – a leading Muslim center of learning – likewise condemned the attacks, calling them a "despicable terrorist bombing that targeted the lives of innocents."
Daesh recently released a video vowing to step up attacks against Christians, who it describes as "infidels".
Egypt's Copts are one of the oldest Christian communities in the Middle East. Egyptian media had previously reported that the church in Tanta had been targeted in the past, with a bomb defused there in late March.