The RUC Chief Constable, Sir Ronnie Flanagan, has described the recent rise in so-called paramilitary-style punishment attacks as "extremely concerning".
There could not be "too strong a public abhorrence to these dreadful attacks" which he said were "tremendously difficult to investigate" due to the reluctance of victims and witnesses to give evidence.
Sir Ronnie made the comments in his monthly report to the Northern Ireland Police Authority.
The authority's chairman, Mr Pat Armstrong, said he believed the onus was on the community as well as on the police to ensure the situation did not further deteriorate.
"Community leaders must condemn these actions in the strongest terms possible. There should never be a reason for anyone to seek out this kind of summary justice. People who carry out these attacks are society's lowest common denominator and should be rooted out and punished by the courts for their evil actions," he added.
According to RUC figures, 23 people were injured as a result of such attacks during April, an increase of 12 on the same period last year. Of the assaults, 14 are being attributed to republican paramilitaries and nine to loyalists.