Colombo, Apr 23 (IANS): The Islamic State on Tuesday claimed responsibility for the Easter Sunday bombings in Sri Lanka that left at least 321 people dead and more than 500 injured.

A statement on the group's official al-Amaq news agency made the claim on the encrypted messaging app Telegram saying the suicide bombers were "fighters of the Islamic State".

The group did not provide any evidence to back the claim, media reports said.

The statement came after an unconfirmed video posted to social media earlier by an affiliated group strongly suggested that the Islamic State was behind the Easter horror.

The video showed photos of three of the alleged suicide bombers.

The men, who are described as "assailants" rather than the more common "martyrs", were named as Abul Barra, Abul Mukhtar and Abu Ubaida and featured in front of a black IS flag giving the one-finger salute, the news.com of Australia said.

Earlier on Tuesday, Sri Lanka's Defence Minister Ruwan Wijewardene said the Sunday attacks were a "retaliation" for last month's Christchurch mosque shooting.