A woman is being treated for burns after an explosion in a block of flats in Neath.
It happened at around 8.30pm on Monday night.
The Waun Las block of flats in Waunceirch has been evacuated due to the extensive damage caused to the building.
All the residents are accounted for and arrangements have been made to house them until the building is deemed safe enough for them to return.
The housing association says that the occupants of four of the flats, which were severely damaged, will not be able to return to their homes for the foreseeable future and they will be found other accommodation.
Three fire crews and one aerial appliance attended the scene.
Wales and West Utilities said they sent a team of engineers to the scene who isolated the gas supply to the affected property.
Wales and West Utilities said the explosion was not related to the mains gas network.
A joint investigation is now underway between South Wales Police and Mid and West Wales Fire and Rescue Service to determine the cause of the incident.
Her injuries are believed not to be life threatening.