Emergency services scrambled to the scene in the Ayrshire town.
Police were called to the under 17s event at Fat Sams on Friday.
Two appliances were sent to the Reform Street restaurant on Sunday morning.
The popular franchise could be eyeing a move into the former Friday's and Go unit on Reform Street.
The local authority is embroiled in a secrecy row about work carried out at the swimming pools.
A man, 72, required hospital treatment after the attack while the woman didn't need medical attention
