One family suspected of being at the heart of the Sri Lanka attacks

Sri Lankan police have revealed at least three of the suicide bombers who attacked Sri Lanka on Easter were from the same family.

The patriarch of this family is one of the country's most successful spice traders.

Y.M Ibrahim, or Ibrahim as police refer to him, resided in a large home with his extended family.

Two of Ibrahim's sons are alleged to have carried out the attacks on Sunday morning.

That afternoon, as police entered the family's home, Ibrahim's daughter-in-law detonated explosives killing three officers and herself, reports the Washington Post.

Neighbours said he and his family kept to themselves, and the women of the family were rarely seen outside.

"He was a good, generous man," said neighbor Piyal Siriwardena. "I'm shocked."

Ibrahim is one of 60 people arrested in the wake of the attacks.

The family was part of an extremist group that had broken away from local militant Islamist outfit National Thowheed Jamaath, according to Sri Lanka's junior defense minister Ruwan Wijewardene.

The group included "quite well educated people" from wealthy backgrounds, according to Wijewardene.

The Islamic State has claimed responsibility for the attacks, but Sri Lankan authorities are unclear of the organisation's role.

Wijewardene claims there is a connection to the Islamic State through "ideology and maybe funding," but the investigation is on-going.

Eight of the nine bombers have been identified by authorities, reports the Washington Post.