Sri Lanka has admitted a major intelligence lapse before the Easter Sunday bomb attacks which killed 359 people and wounded more than 500.
Parliament heard an Indian intelligence warning from the beginning of the month about planned attacks was not properly shared by the authorities.
Sri Lanka's President Maithripala Sirisena has moved to sack the defence secretary and inspector general of police.
The sister of the attackers' suspected ringleader has strongly condemned him.
Eight of the nine attackers have been identified as Sri Lankan citizens.