Islamic extremists carried out Sunday's coordinated attacks in retaliation for a March attack on two mosques in New Zealand, said Ruwan Wijewardana, the Sri Lankan State Defense Minister.
Addressing parliament today, Wijewardana said that initial investigations showed "the chain of bombings" was carried out by "a radical Islam group" which he named as the National Tawheed Jamath (NTJ).
The Islamic State group is claiming responsibility for the attacks but has offered no evidence. The extremist group made the claim Tuesday on its Aamaq news agency.
“The perpetrators of the attack that targeted nationals of the countries of the coalitions and Christians in Sri Lanka before yesterday are fighters from the Islamic State," the claim said.
321 people died in the Easter Sunday bombing attacks.
Last month's mosque attack in Christchurch, New Zealand, saw at least 50 people murdered in a shooting rampage by a white supremacist. The rampage began at lunchtime on a Friday, when mosques were full of worshippers.
This story is developing... check back for updates.