At least 36 people were killed and more than 100 injured in bomb attacks on two Coptic churches on Palm Sunday, in the latest assault on a religious minority increasingly targeted by Islamist militants.
There was no immediate claim of responsibility for the attacks.
The first bombing, in Tanta, a Nile Delta city less than 100 kilometres outside Cairo, killed at least 25 and injured at least 78, Egypt's Ministry of Health said.
The second, carried out just a few hours later by a suicide bomber in Alexandria, hit the historic seat of the Coptic Pope, killing 11, including three police officers, and injuring 35, the ministry added.
The bombings come as Islamic State's branch in Egypt appears to be stepping up attacks and threats against Christians.
In February, Christian families and students fled Egypt's North Sinai province after a spate of targeted killings.
Those attacks came after one of the deadliest on Egypt's Christian minority, when a suicide bomber hit its largest Coptic cathedral, killing at least 25. Islamic State later claimed responsibility for the attack.