The hand grenade was removed from a suspect’s pocket after they were apprehended on Saturday night.
“The grenade is not used by police; it’s used by the military and investigations will definitely continue to find out the source of that grenade,” said Lae metropolitan superintendent, Chris Kunyanban.
“We’re coming towards the (2022) elections and weapons like this, especially the hand grenade, is a concern to us because in the last election in Lae alone, we confiscated a lot of C-4, explosives.”
The grenade was among a number of firearms confiscated following a robbery at Markham Haus on Saturday night.
A shootout ensued soon after along Butibam Road, where two suspects were killed and three others injured.