Five fire engines, a fire rescue unit and around 30 firefighters have been called to reports of a fire and explosion in what is believed to be a workshop on Denmark Hill, close to Coldharbour Lane in Camberwell, SE5.
Around half of the ground floor of the building has been damaged. Early reports suggest that one man has been taken to hospital by ambulance.
Firefighters from Brixton, Peckham, Old Kent Road and Lewisham are on the scene. The Met Police and London Ambulance Service are also there.
The Brigade was called at 1417.
More top news
A prison officer - who was allegedly assaulted by a prisoner at a crown court - has died.
Large plumes of black smoke could be seen coming from the boat which caught fire while anchored on the River Thames.
London mayor Boris Johnson is under pressure to issue health warnings about his new double decker bus during the heatwave.