Northern Ireland Police Federation chairman Terry Spence, who represents rank and file officers, praised his "brave" colleagues on their find.
He said the weapons were "undoubtedly intended to murder officers" and that there is "hiding place for terrorists".
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Protesters across Europe and the rest of the globe held women's marches following the inauguration of President Trump.
A look at some of the inventive, and sometimes humourous, placards displayed in women's marches across the UK.