A nearby resident, who did not wish to be named, thought she heard more than 12 rounds of gunshots going off.
"Sounded like fireworks going off but [was] consistent," she said.
"I thought to myself who the heck would set off fireworks at 4 in the morning. About 20 minutes later the chopper was flying around."
She said neither she nor her neighbours could go back to bed afterwards.
"We hope no one was hurt," she said.
One Facebook user wrote on the Ellerslie community page that she heard gunshots from the Fight Club clubrooms at Marua Rd.
"Sounded like automatic gun fire then the helicopter went up," she wrote this morning.
"Partner went to the gym at around 4.30, Marua Rd was closed from Mitre10 to Lunn Ave. Police everywhere with weapons. Scary stuff in our own backyards."