Cowards who prompted a bomb alert near a cenotaph in Tyrone are sickening, police said.
A suspicious object was discovered on Sunday morning in Omagh and the area has been closed off.
A senior officer said it was too early to say whether the Remembrance Sunday ceremony will be affected.
PSNI chief inspector Graham Dodds said: “This is a sickening attempt by cowards to create fear and disruption on a day when many gather to pay their respects to the brave men and women who paid the ultimate sacrifice, and must be unreservedly condemned.”
Many people are due to attend the event at the cenotaph.
The chief inspector added: “I would like to reassure the public that we are working hard to make the area safe and that we will continue to provide updates on any impact to today’s event.”
West Tyrone DUP MLA Tom Buchanan expressed his disgust at those behind the security alert.
“Remembrance Sunday is a day when we pause to commemorate all those from every background who paid the supreme sacrifice. It is disgusting that anyone would target a war memorial at any time, but on Remembrance Sunday it is an act of particular hatred.
“Omagh has a long association of service within our Armed Forces and those who served came from all backgrounds and traditions. The cowardice of those who left this device stands in stark contrast to the bravery of those who are commemorated today.
“Whilst the annual Remembrance Service has been able to continue in Omagh Academy, there has been an impact on the events which would normally take place. It is right that the security forces take all the necessary precautions and I would pay tribute to their efforts in keeping people safe.”