Tanta, Egypt: At least 44 people were killed in bomb attacks on two Egyptian Coptic churches on Palm Sunday that included the seat of the Coptic Pope, the latest assault on a religious minority increasingly targeted by Islamist militants.

Islamic State claimed responsibility for the two church bombings, the group's news agency Amaq said.

"A group that belongs to Islamic State carried out the two attacks on the churches in the cities of Tanta and Alexandria," Amaq said.

The first bombing, in Tanta, a Nile Delta city about 100 kilometres north of Cairo, tore through the inside of St George Church during its Palm Sunday service, killing at least 27 people and injuring at least 78, the Ministry of Health said.