Four fire engines and around 25 firefighters attended a gas leak next to a doctor's surgery on Jonathan Street in Vauxhall.
Two people were assessed by London Ambulance Service crews at the scene and a 100 metre cordon was put in place, which was reduced to 50 metres by the evening.
Around 200 people from neighbouring residential buildings were evacuated as a precaution. A respite centre was set up at a local church for those who have been displaced from their homes. Multi-agency service partners worked together to provide temporary accommodation overnight for those displaced from their homes.
Multi-agency service partners have worked overnight to isolate the leak and make the area safe.
The Brigade was called at 0433 and the incident was over for firefighters by 1101; however, crews and officers remain on scene.