City disturbance brought to a premature conclusion (3)

I believe the answer is:

rio

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'city' is the definition.
(Rio de Janeiro)

I don't understand how the rest of the clue works.

(Other definitions for rio that I've seen before include "Flying Down to -, Astaire, Rogers film" , "A Mexican river, may be grande" , "old capital" , "Manchester United player in South American city, in short?" , "- Ferdinand, footballer" .)

I've seen this clue in The Telegraph.

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