Firefighters were called to a car alight in the northbound tunnel of the Blackwall Tunnel at Greenwich.
One vehicle was badly damaged by the fire. Around 100 people were evacuated from the tunnel by the Metropolitan Police Service. Fortunately, there were no reports of any injuries.
The Brigade's 999 Control Officers took 10 calls to the blaze.
The Brigade was called at 1008 and the fire was under control by 1046. Four fire engines from Poplar, Millwall, East Greenwich and Greenwich fire stations were at the scene.