At least 13 people have been killed and 25 have been injured after a bomb exploded inside a packed Egyptian church.

The blast happened at St George Coptic Church, in Tanta, north of Cairo, just before 10am local time, according to Al Arabiya News channel. The incident comes as worshippers gathered for the celebrations of Palm Sunday – which marks the start of Holy Week for Christians.

Footage from inside the church have emerged showing a dozens laying injured from the blast. Coptic Christians make up around 10 per cent of Egypt’s population and have repeatedly been targeted by Islamic extremists. Last year, 25 people were killed in a suicide bombing that targeted one of Egypt’s largest Coptic cathedrals.