Northern Ireland is on terror alert, just days after it was announced the Queen would visit next month.
The Police Service of Northern Ireland issued a warning of an increased terrorist threat.
It said it was "stepping up operations across Northern Ireland to disrupt dissident republicans".
The public would notice increased police activity, including the use of vehicle checkpoints, said a statement.
Checkpoints and other overt security measures have hardly been seen in recent times following the return of devolution last year.
The PSNI said: "The public are urged to be patient and to co-operate with police in this operation which is designed to ensure the safety of the whole community."
The warning came two days after the dissident Real IRA used a Dublin-published Sunday newspaper to claim it was going on the offensive again.
That threat itself came two days after it was announced from Buckingham Palace that the Queen would visit the province on the Thursday before Easter to distribute Maundy Money outside The Church Of Ireland Cathedral in Armagh - the first time a monarch has carried out the ceremony outside England and Wales.
It was thought to be the first time an announcement of a royal visit to Northern Ireland had been announced so far in advance.
Normally such announcements are not made until the royal visitor is actually within the province.Reuse content