His reaction was contained in a statement by the Force Public Relations Officer, DCP Frank Mba, on Friday.
The IG said the Thursday incident resulted in the death of a policeman, Cpl. Etaga Stanley, attached to ‘A’ Division, Ughelli.
Adamu added that the attack also left Sgt. Patrick Okuone with injury from gunshot by the protesters.
He said protesters took the deceased’s service AK47 rifle with breach no 56-2609008 and 25 rounds of live ammunition.
Adamu commiserated with the officer’s family and ordered the Commissioner of Police in Delta to bring the killers to book.
Adamu described the incident as cruel and unwarranted.
The IG warned that Police would no longer tolerate any attack on its personnel or any member of the law enforcement community.
Noting that protests are legitimate rights of citizens, he said they, “must be carried out with all sense of responsibility and within the confines of the law’’.