Sri Lankan intelligence has named the mastermind behind the Easter Sunday attacks as Moulvi Zahran Hashim, an extremist local cleric who incited his followers to violence with fiery sermons on his social media channels.

The revelation comes after senior government officials accused the National Thowheed Jamath (NTJ) a little-known group promoting Islamist terrorist ideology, as the perpetrators of the horrific suicide bombings which have now killed 310 people, including eight British citizens.

India’s CNN News 18 channel first reported the possible involvement of Hashim in the massacre, claiming that Indian intelligence sources had indicated to the Sri Lankans that he was planning to attack the Indian High Commission in Colombo in early April.

An initial probe into deadly suicide bomb attacks in Sri Lanka that killed more than 300 people shows it was "retaliation for Christchurch," the country's deputy defence minister said Tuesday.

"The preliminary investigations have revealed that what happened in Sri Lanka (on Sunday) was in retaliation for the attack against Muslims in Christchurch," state minister of defence Ruwan Wijewardene told parliament.