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The mock exercise centred around an alleged chemical attack in a Wrexham factory

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There were a number of "casualties" after the controlled explosion

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Wrexham Industrial Estate was cordoned off and the emergency services set up their equipment

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Members of the emergency services wore protective clothing

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The pretend victims were stripped of their clothes and forced to wear special robes

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Two decontamination units were set up for volunteers to walk through and shower

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The "injured" were taken to a special reception area where their details were processed