The Sri Lankan Minister of Defence has reportedly said the church and hotel attacks that killed 321 people over Easter were retaliation for the Christchurch shootings.

"The preliminary investigations have revealed that what happened in Sri Lanka was in retaliation for the attack against Muslims in Christchurch," Ruwan Wijewardene told parliament on Tuesday afternoon.

But Prime Minister Jacinda Ardern's office says New Zealand officials haven't seen any intelligence upon "which such an assessment might be based".

The attacks happened at separate locations on Easter Sunday in Sri Lanka with churches and hotels targeted.

The first explosion hit St Anthony's Church around 8:45am on Sunday (local time) as the Easter Mass took place, according to local journalist Roel Raymond.

Minutes later, another explosion ripped through St Sebastian's Church and the Zion Evangelical Church in Batticaloa, before three hotels were reportedly attacked - the Kingsbury Hotel, Shangri-la Hotel and Cinnamon Grand Hotel in Colombo.

The Guardian reported an intelligence memo circulated to some in the Sri Lankan government in the weeks before the attack said one member of a local terrorist group identified as having perpetrated the bombings had started to update his social media accounts “with extremist content” in the aftermath of the shootings by a rightwing-extremist in New Zealand.

