Indian intelligence agencies had warned their Sri Lankan counterparts about a possible terror attack hours before a series of explosions ripped through the island nation, killing at least 321 people on Easter Sunday, Reuters quoted sources as saying.
Indian intelligence officers contacted their Sri Lanka counterparts two hours before the first attack to warn of a specific threat on churches, Reuters quoted one Sri Lankan defence source and an India n government source as saying.
Moreover, the Indian government source said similar messages had been sent Sri Lankan intelligence agents on April 4 and April 20.
The Islamic State has claimed repsonsibility for the attack and identified the seven suicide bombers who were involved in the attacks.
In a statement issued through its propaganda 'Amaq' news agency, the ISIS said that "the executors of the attack that targeted citizens of coalition states and Christians in Sri Lanka two days ago were with the group," according to the Site Intelligence Group, which monitors jihadist activities.
The statement identified the attackers as Abu Ubayda, Abu al-Mukhtar, Abu Khalil, Abu Hamza, Abu al-Bara'a, Abu Muhammad and Abu Abdullah, and their respective targets.
It also claimed that around 1,000 people were killed or wounded in the blasts.
"The detail given in #ISIS' communique (attackers' names, where each of them attacked) shows that the group had a hand in the attack - the degree to which still remains to be seen. The group's delay in claiming is also an unanswered variable," SITE Intelligence Group Director Rita Katz tweeted.
Sri Lanka has said local Islamist extremist group called the National Tawheed Jamath (NTJ) is suspected of plotting the blasts.
"All suicide bombers involved in the blasts are believed to be Sri Lankan nationals," said Government's spokesman Rajitha Senaratne, who is also the Health Minister.
Forty suspects, including the driver of a van allegedly used by the suicide bombers, have been arrested in connection with the attacks which shook Sri Lanka.