A photographer at the scene said there were about six police combing the area for a cartridge.
Owner of Mamaku Garage Adam Ducre said police had blocked off a small section of road on the corner of Umuroa and Turoa Sts.
He said he had woke up to the sound of gunshots about 4am and seen four police cars in the area.
"Nobody knows what it's about... this is unusual around here, it's been so quiet lately."
A local resident, who wished to remain anonymous, said there had been increased tension on Umuroa St the last few days due to a spike in local thieving.
She said the number of break-ins around that area had been especially bad lately.
A worker at the Mamaku Grocery Store said a lot of residents had been asking about what was going on but no one was really sure.
He commuted from Hamilton to Mamaku for work everyday and had never seen such a large police presence in the area.
Residents on a local Facebook noticeboard reported hearing the gunshots, with some saying it woke them up before sunrise.
One said she was lying in bed and heard around five to eight shots then a small pause and a couple more shots.
"I cant specifically say how many but it sounded like it was my end (of the street). I put it down to duck shooting season.
"I saw a couple of under cover cop cars around 9.30am and around five cops on road in front of an address."