Cairo, Egypt: The Islamic State group claimed responsibility for bombing two Egyptian churches on Sunday in the deadliest attacks on the country's Christian minority in recent memory.

"Islamic State squads carried out the attacks on two churches in Tanta and Alexandria," said the group's self-styled Amaq news agency in a statement published on social media accounts.

The first bombing struck a church in the city of Tanta north of Cairo, killing 25 worshippers.

The other attack, which the interior ministry said was caused by a suicide bomber, killed 11 people at a church in Alexandria.

The ministry said Coptic Pope Tawadros II was inside the church leading a Palm Sunday service when the suicide bomber was stopped by police outside and blew himself up.

A church official said Tawadros had already left the church when the bombing took place.

IS had claimed last December's bombing of a Cairo church that killed 29 people, and threatened further attacks on Egyptian Christians.