“In all probability, the fire started because of the chemical and spread to the upper floor,” he said, adding that the cause of the fire was under investigation.
Deputy Commissioner of Police Venkateshwarlu said the fire started due to a spark in a car which was being repaired in the ground floor.
He said preliminary investigations show that six persons died of suffocation as the smoke engulfed the upper floors.
There were six families living in six flats on the first, second and third floors.
There was no one on the fourth floor.
Officials say since the building does not come under high-rise category they assume it had building permission.
However, the chemical was apparently stored illegally. The director of fire safety said the fire reportedly started around 8.30 a.m. but the fire services received the call at 9.35 a.m.