Local media showed pictures of Sri Lankan military officers entering the suspects’ building during the raid and smoke billowing from it after an explosion.
The Easter Sunday bomb blasts at three churches and four hotels in Sri Lanka killed more than 200 people and wounded at least 450, police officials said, the first major attack on the Indian Ocean island since the end of a civil war 10 years ago.
The government declared a curfew in Colombo. It is unclear when the curfew would be lifted.
There were no immediate claims of responsibility for the attacks.
(Production: Akshata Rao)