Almost 30 fire crews are battling a blaze at a bowling alley in the heart of Great Yarmouth.
Police, the fire service and ambulance crews were called to Regent Superbowl in Regent Road, the town's main tourist street close to Britannia Pier, at around 3.20am on Friday.
A cordon has been put in place and nearby properties have been evacuated as a precautionary measure, with a number of road closures in place.
A Norfolk Police spokesman said: "It is too soon to confirm the cause of the fire, which appears to be under control, however there is a large amount of debris in the area.
"No-one has been reported injured at this time."
The fire service confirmed 29 appliances were tackling the fire and the building had partially collapsed.