“Fireworks were thrown into the building, causing a fire and putting lives at risk,” O’Callaghan said.
“This was a terrifying ordeal for the women and children living there, a number of whom were taken to hospital.”
He said alternative accommodation is now being sourced for the residents affected.
“A full Garda investigation into this arson attack is underway. There will be serious consequences for those responsible.”
Taoiseach (Irish prime minister) Michéal Martin has said he condemns “in the strongest terms the deeply disturbing incident”.
“To put vulnerable families, including young children, at risk is abhorrent and has no place in our society,” Martin said.
“Our thoughts are with those affected by this horrifying experience.”
Gardaí said the scene has been technically examined and a senior investigating officer has been appointed to lead the investigation.
Anyone with information regarding the incident is asked to contact gardaí.
