Veni and her six-year-old daughter Kiran were killed when the LPG gas cylinder kept in their bedroom exploded, they said.
Police said initial investigation suggests it to be a case of suicide.
The incident occurred when Veni's husband Sibu was away from their apartment in Prashant Nagar in Edappally, they said.
The neighbours informed police when they noticed fumes coming from the victim's apartment.
Though the police rushed the woman and her daughter to a hospital in the neighbourhood, they could not be saved.