Dissident republicans are becoming increasingly reckless and the threat remains severe, the chief constable of the PSNI has said.
Matt Baggott met officers at Strand Road police station in Londonderry following last week's car bomb attack.
Last Tuesday, a car packed with 200lbs of homemade explosives went off outside the station.
He said that the bombers "are the same people, or the same mindset that ultimately led to the Omagh tragedy".
On 15 August 1998, 29 people, including a mother pregnant with twins, were killed when a Real IRA bomb went off in the centre of Omagh, County Tyrone.
No-one was injured in the attack on the police station in Derry, but a number of businesses were badly damaged.
The chief constable added that the dissidents were becoming increasingly "reckless".
"They have no solution for the future, only to go back to the past. And they are bringing that recklessness increasingly to our streets," he said.
"We need the public to fully support us and don't allow these people to do what they want to do.
"They are dangerous. We need to be realistic about them and keep them firmly on the back foot."
On Saturday, a bomb was found under the car of a Catholic police officer in Kilkeel and on Wednesday, a booby-trap bomb fell from the underside of a car belonging to an army major in Bangor.