A blaze tackled by around 100 firefighters that spread across five terraced houses is believed to have started in a domestic heating oil tank.
Several people were evacuated overnight following the major fire in Well Lane, near Falmouth in Cornwall, which broke out at about 8pm last night.
All the occupants had been accounted for and several people had been rescued, the Cornwall Fire and Rescue Service said.
A spokesman added 10 major fire appliances were sent to the incident.
"Around 100 fire and rescue service personnel were directly involved in this incident," he said.
"The fire is believed to have started in the vicinity of a domestic heating oil tank and affected five properties.
"All persons are accounted for but several people have been evacuated from the immediate area and are being re-housed in the local area."
A Devon and Cornwall Police spokesman said people who were evacuated stayed overnight with friends and family in the village.
A Fire Service investigation team is due to continue its investigation today to "firmly" establish the cause of the incident.
Parts of Well Lane will remain closed until mid-morning.