The Guardian reported that minister Ruwan Wijewardene told the parliament earlier today, 23 April, that the attacks were a response to the mass shooting at a mosque in Christchurch, New Zealand last month.
"Preliminary investigations have revealed that what happened in Sri Lanka was in retaliation for the attack against Muslims in Christchurch," he said, according to Channel NewsAsia.
Ruwan added that the death toll has risen to 321 people including 38 foreigners, as opposed to the previously reported 290.
Meanwhile, a cabinet minister claimed that local Islamist group National Thowheeth Jama'ath (NTJ) was responsible for the attack
Asia Times reported that minister Rajitha Senaratne added that the NTJ was not alone in carrying out the bombings, and received support from "international networks".
"We don't see that only a small organisation in this country can do all that... We are now investigating the international support for them," Rajitha said.
"(We are probing) how they produced the suicide bombers here, and how they produced bombs like this," he added.
One member of the group reportedly began updating his social media accounts "with extremist content" after the Christchurch mass shooting
According to The Guardian, an intelligence memo revealed information about the terrorist group member weeks before the bombings, and was circulated to some in the Sri Lankan government.
However, The Guardian quoted terrorism researchers as saying that the Easter Sunday attacks would possibly have required months of preparation, as it takes time to condition the suicide bombers and test the explosive devices.