Firefighters were called to reports of a fire and suspected explosion in a block of four maisonettes on Amberley Court in Sidcup this morning.
When crews arrived there was no fire apparent but the explosion had caused structural damage to a first floor maisonette.
One man left the property before the Brigade arrived. Crews evacuated a further five people - four adults and a child - from neighbouring properties and isolated the gas supply. London Ambulance Service was also at the scene and took one person to hospital.
Crews were called at 1047 and the incident was over for the Brigade at 1212. Three fire engines and a fire rescue unit from Sidcup, Eltham, Orpington and Bexley fire stations attended the incident. The cause of the suspected explosion is under investigation.