A masked member of the Real Irish Republican Army (RIRA) splinter group reads a statement
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Real IRA threat to police officers

25 April 2011 Last updated at 22:35 BST

The dissident republican group, the Real IRA, has threatened to kill more police officers, and declared it will oppose the Queen's first visit to the Irish Republic next month.

The warnings came in a statement read out by a masked man at a cemetery in Londonderry.

Mark Simpson reports.