At least 21 people have been killed and 50 others wounded in an attack on a Coptic Christian church in northern Egyptian city of Tanta.

The blast occurred as Coptic Christians were marking Palm Sunday, so the church was packed at the time of the attack.

This is not the first time Christians in Egypt have come under attack. In December, 25 people were killed by a suicide bomber at Cairo’s main Coptic cathedral.

ISIL militants later claimed responsibility. The group has also threatened to specifically target Christians in the country.

Coptic Christians have been fleeing the Sinai region where ISIL is active. They have been given alternative accommodation by the Egyptian government.