Chief superintendent, Chris Kunyanban, is urging residents to help police if they have information on the whereabouts of hand grenades, C4 or illegal firearms.
Lae police confiscated a hand grenade, among other firearms, from suspects who robbed gold buyers on the night of Saturday, the 26th of June.
It was during that time that two of them were killed at Bumbu.
Lae metropolitan superintendent, Kunyanban, said police are concerned as explosives were used in the last elections.