Firefighters were called to the corner of The Cut and Blackfriars Road on Sunday lunchtime when fire broke out at the Baltic restaurant.
Sunday lunch diners fled as smoke both filled the restaurant. Meanwhile smoke was pouring from the roof of the kitchen. Residents of Ring Court above Costcutter said that they had a wall of smoke outside their windows.
The fire alarm could be heard ringing in Southwark College as fire appliances from Old Kent Road and other fire stations arrived in both The Cut and Burrows Mews. A control centre was set up in Ufford Street.
The cause of the fire is not known.