Sri Lankan President Maithripala Sirisena has asked the police chief and defence secretary to step down following the Easter Sunday attacks.
This comes as new reports showed that Sri Lankan intelligence officials were tipped off about the attacks hours before it actually happened by their Indian counterparts.
Investigators have identified eight of the nine suicide bombers who carried out the Easter Sunday bombings that left 359 people dead and 500 more injured. One of the attackers was a woman, deputy defence minister Ruwan Wijewardene told reporters on Wednesday, with 60 arrests made so far.
Earlier on Wednesday, Sri Lankan police carried out a controlled explosion of a suspicious motorscooter parked near the Savoy cinema in the capital Colombo.
Meanwhile, Washington's ambassador to Colombo said the US believes there is ongoing terrorism plotting in the country.

Trump says Iran war to end after US midterm elections
Search expands after Philippine ferry fire kills five and leaves dozens missing
US military says it struck vessel in Caribbean, killing 3
At least 14 killed in explosion at weapons depot in Syria
US hits five Iranian oil tankers after attack on Navy ships
UK gives air traffic provider a week to probe outage that halted flights
Serbia's President Vucic dissolves parliament, calls snap elections
With large crowds attending, Norway lays King Harald to rest
