The incident took place at Sector 23 in Sajnay Colony while a pregnant 28-year-old Anju was cooking, a police spokesperson said.
Besides Anju, her 40-year-old husband Nandkishor and their daughters 4-year-old Doly and one-and-half-year-old Laxmi suffered serious burns and were admitted to a nearby hospital by neighbours, the spokesperson said.
Since the victims are in a serious condition, they have been shifted to a hospital in Delhi, the spokesman added.