According to the source, the brothers were sons of a wealthy spice trader. They carried out the suicide attacks while they were standing in a queue at the Shangri-La and Cinnamon Grand hotels in Colombo.
Apart from that, the news agency reported, citing sources familiar with the investigation, that another suicide bomber had tried to commit one more explosion at a hotel in Colombo on 21 April, but his plan failed, AFP reported.
Multiple explosions took place in Sri Lanka on Easter Sunday; three churches and three hotels were targeted; the blasts killed more than 300 people.
Sri Lankan authorities launched a massive security operation after the tragedy. At least 29 people were detained in connection with the attacks. Interpol announced Monday it would deploy a special team to Sri Lanka to investigate the waves of deadly bombings.