A two-storey house in central Christchurch caught fire yesterday prompting a hasty exit by its intoxicated occupants, including one man who did not even pause to grab clothes.

The naked man, aged in his 50s, was seen scrambling down a fire escape shortly after smoke began pouring from the house about 4pm.

Assistant area fire commander Greg Crawford said the five were in various states of drunkenness but all managed to escape.

"St John is looking after some, some have disappeared," he told The Press.

"They are in no state to look after themselves."

The fire's cause was not yet known.