Gardaí and emergency services were called to Balbutcher Drive in Ballymun, Dublin 11 shortly before 4pm yesterday, August 16.
Those who died were very closely associated with a criminal shot dead and whose body was dumped in a laneway in Dublin 3½ years ago.
It is understood the pair who were killed may not have been the intended targets.
She said that two men pulled up to the house and one opened fire "indiscriminately" at the house, which had children inside.
"Two others a woman and a man are being treated for less serious injuries at the Mater Hospital".
Gardaí said there were other children in the home when the shooting took place.
Meanwhile, a second auto is being examined in relation to the attack - Golf GTI, registration 06 LH 3466.
Local Social Democrat TD Roisin Shortall said the community feared an escalation of the gangland violence recently seen in the area.
Sinn Fein TD forDublin North West, Dessie Ellis, urged people to "desist", saying: "Nobody should be targeted, nobody should retaliate or get involved".
The shooting occurred on Balbutcher Drive in the Poppintree area.
The area was sealed off with Garda scenes of crime officers expected to carry out forensic examinations.
A silver Opel Zafira with 08 LS plates was found partially burnt out nearby and Gardaí are appealing for information on its movements.