Police face a severe threat from dissident republicans in the wake of separate bomb attacks, a senior officer has said.
Assistant Chief Constable Drew Harris spoke out after police were lucky to escape blasts in Belfast and Londonderry.
The senior officer said a murder bid by Republican Action Against Drugs (RAAD) in Derry was a response to the pressure detectives have placed on the grouping.
That attack on Saturday damaged a police vehicle and was followed on Wednesday when the Oglaigh na hEireann group targeted police with an improvised grenade in Twinbrook.
Mr Harris said of the threat from dissident groups: "It is a particular concern given the attacks and also then the amount of devices we have retrieved as well. But we have had success in bringing people into the criminal justice process.
"Going forward, the threat is severe and our officers have to work in that environment. We have to make sure that our response is appropriate to that threat."
His comments came as police launched efforts to tackle so-called punishment beatings and shootings.
In the last year there have been 79 punishment attacks, including 31 assaults carried out by loyalists and 15 beatings by dissident republican groups. Dissident republicans were responsible for all 33 shootings included in the figures, police said.
The senior officer conceded that the 4% detection rate for police dealing with the crimes had to be improved. He revealed that officers are to use a new Facebook page to encourage young people to help combat the activity.
He also said detectives will use tactics employed against organised crime to target those engaged in such attacks.