The Chief Constable of the Police Service of Northern Ireland, Matt Baggott, has said dissident republican groups are trying to outdo each other.
Mr Baggott said the groups are in competition when it comes to the number of attacks they carry out.
He said that the "recklessness of their attacks is beyond measure".
Mr Baggott made the comments following an explosion in Lurgan, County Armagh, on Saturday.
It is believed that the explosion was an attempt to kill police officers.
Mr Baggott said: "All of these five attacks in the last month could have killed innocent members of the public.
"There is a competiveness between these groups at the moment which is completely irrational but could end up in a very real tragedy indeed."