Relatives of those killed by the Omagh bomb blasts have called for a meeting with the PSNI's Chief Constable, Hugh Orde.
The call follows revelations that anti-terrorism intelligence was withheld before the 1998 atrocity.
Allegations that MI5 failed to inform Special Branch of the threat emerged during an investigation into an FBI agent who infiltrated the Real IRA.
The agent, David Rupert, said dissident republicans planned to carry out bomb attacks in Derry or Omagh. However, Mr Orde said this involved a different unit.
