The incident took place last night in Zakir Nagar area under the jurisdiction of Jamia Nagar police station of south-east Delhi, police said today.
According to the fire department, following a call of fire at around 1.30 AM today, two fire tenders were sent to the spot which took almost 30 minutes to douse the fire.
The house where the fire broke out belonged to one Firoz (35), who lived there along with his wife Yasmin (32) and four children, Afroz (12), Afreen (11), the only daughter, Asif (7) and Aamir (4).
As the police probe the matter to zero in on the exact cause of the fire, they have been confronted by several unanswered questions. Neighbours claim to have heard no scream or distress call from the house initially and rushed to save them only after seeing the smoke and flames.