Gardaí investigating the murders of Tadgh Farrell and his grand-aunt Mary Holt are carrying out searches of three houses in Kildare and Offaly this morning.
Officers from the Serious Crime Unit of the Laois/Offaly Garda division are involved in the search operation.
Investigating gardaí are being supported by other units including Special Tactics and Operations Command, the National Bureau of Criminal Investigation, and divisional gardaí from Laois/Offaly and Kildare/Carlow.
Gardaí are continuing to appeal for information in relation to the fatal attack.
Earlier this week, gardaí released CCTV footage of the attack in Edenderry.
Watch: CCTV footage showing moment of Edenderry arson attack
Tadgh Farrell, who was four years old, and Ms Holt, who was 60, died after a fire broke out at a house in Castleview Park in the town on Saturday night.
Tadgh and Ms Holt were in a front room downstairs in the house when a suspected petrol bomb was thrown through the window.
It is understood the house had been targeted previously.
In the footage, two people are seen approaching the house at around 7.45pm on Saturday night.
A suspected petrol bomb is seen thrown into the front downstairs window of the house before it bursts into flames. The two people then flee the scene.
Tadgh's grandmother continues to receive hospital treatment for serious burn injuries.
