Trouble flared at the fourth Norwich Sci-Fi and Film Convention at the University of East Anglia, organised by Norwich Star Wars Club.
Police were called after members of the rival Norwich Sci-Fi club arrived to get autographs from two Doctor Who actors at the event on Sunday.
Norfolk Police confirmed officers attended and spoke to both parties.
A spokesman said they had been called to reports of a man being assaulted at the convention.
Star Wars and Doctor Who fans clash at Norwich convention
One thing is for sure; if there had been Star Trek fans at this convention, they would have mediated peace.
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