AKIPRESS.COM - ISIS has claimed responsibility for the Sri Lanka suicide bombings that killed 321 people and injured 500 others.

Sri Lanka's government has blamed two domestic Islamist extremist groups for carrying out the attack, but believes they had help from an international network, The Mirror reported.

The early findings of the investigation have found that the attacks were committed in revenge for the mosque shootings in Christchurch, New Zealand, a month ago, a junior minister told parliament.

It had been speculated that a group such as ISIS could have provided support to the domestic extremists, and one of the groups had been described as a branch of the terror group recently driven out of its final bastion of territory in Syria.

ISIS claimed responsibility for the attacks in a message posted Tuesday by its Amaq propaganda agency.

It did not provide any evidence to support its claim.

Both ISIS and al-Qaeda had called on revenge attacks after the Christchurch terror shootings.

Sri Lankan police have arrested 40 people as part of the investigation into the bombings of three churches and three hotels, and one was a Syrian national, a source told Reuters.