Egypt has arrested suspects accused of involvement in the Cairo church bombing that killed 27 people, its interior ministry announced on Wednesday.

The bomb struck the church of St Peter and St Paul during Sunday mass on December 11, leaving 28 dead and more than 40 wounded. Varying reports state that arrests total three or four suspects. This is in addition to the four who were detained in December. 

One of those whose arrest has been announced is Karam Ahmed Abdel-Asl Ibrahim, one of the alleged ringleaders, AFP reports. The interior ministry said that the suspects were planning further attacks and improvised explosives, weapons and ammunition were seized in the arrest, according to Reuters. One of those arrested has links to the Qatar-based Islamist movement the Muslim Brotherhood, though the group has denied any involvement.

ISIS claimed responsibility for the attack in December, calling it a "martyrdom operation" targeted at "infidels" and "apostates".

Eqypt's President Abdel Fattah al-Sisi has named the suicide bomber as Mahmoud Shafik Mohamed Mostafa, 22.

The small church where the attack took place is next to St Mark's Coptic Orthodox Cathedral, the seat of the Coptic Pope. It is the deadliest attack on Coptic Christians since the bombing of Two Saints Church in Alexandria on New Year's Eve of 2011, where more than 20 worshippers were killed.

Egypt has an estimated population of nine million Christians. Mostly Orthodox Copts, they account for about 10 per cent of Egypt's population, which is overwhelmingly Sunni Muslim. Some of the survivors of the St Peter and St Paul bombing said that they forgave their attackers, and were willing to die for their faith.