Ilham Ahmed Ibrahim -- one of two sons of a spice tycoon who blew themselves up in Sunday's attacks -- detonated a device at the Cinnamon Grand hotel in Colombo, the official told CNN.
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In an interview with CNN, Sri Lanka's Prime Minister Ranil Wickremesinghe said the suspected bombers were upper and middle class, well-educated and educated abroad, a profile he described as "surprising." He added that several of them were under surveillance ahead of the attacks, but that there had not been "sufficient" evidence to take them into custody.