Police say a feud between the Nomads and Comanchero bikie gangs for supremacy in Canberra's south is behind a recent spate of shootings and arson attacks.
A machine gun – similar to an AK-47 - was used to spray a house linked to a Comanchero bikie in a recent late night attack, raising the risks an innocent bystander could be caught in the crossfire and seriously hurt, police say.
A Kambah home linked to a Nomads member had been targeted only days earlier, with shots fired into the door and three cars torched.
ACT Policing's anti-bikie Taskforce Nemesis was investigating the possibility the use of the automatic assault rifle was a reprisal shooting, or whether the attacks had been sparked by internal gang rifts.
Chief Police Officer Justine Saunders admitted she had been "alarmed" by the surge in violence and use of firearms as police probed five firebombings and drive-by shootings in recent months.
"If we have, as we've seen, bikie gangs using AK-47s and other serious firearms, and if they're driving by residential homes and shooting at them, I just think it's a matter of time before an innocent person gets caught up in that and gets injured or killed."
Assistant Commissioner Saunders said the most recent attacks had been driven by rivalry between the Nomads and Comanchero.
In the latest attack, 27 shots were fired into cars and the front of the house on Badimara Street in Waramanga shortly after 11pm last Tuesday.
Residents of the suburb described hearing loud bangs and reported a car leaving at high speed.
The same property had been targeted by gunfire in 2015.
Police said on Monday no arrests had been made in relation to either shooting.
Tensions between bikers have flared in recent years as small groups of the Rebels, who were Canberra's sole bikie gang for decades, patched over to set up local chapters of the Nomads and Comanchero.
"Currently what we're seeing is rivalry behaviour between outlaw motorcycle gangs. It is about patching over, it is about relationships, it's about criminal activity," she said.
"This is about serious organised criminals acting in a violent way towards each other. So that's a huge concern to me."
Assistant Commissioner Saunders said she'd directed taskforce members to take "all action possible" to prevent and disrupt bikie gang activity as the attacks continued.
She flagged a potential push for tighter gun laws and bolstered powers to help officers secure evidence from crime scenes linked to bikies when property owners resisted police intervention.
But she "wasn't wedded to a particular solution".
"Let's be honest, in circumstances like what we've seen [last Tuesday night] they're not consenting, they're not co-operating with us and yet we have an obligation to investigate that crime, find the perpetrators and bring them before the court."
Assistant Commissioner Saunders said anti-fortification measures were "a useful tool" and has voiced support for anti-consorting laws - which the ACT government abandoned over human rights concerns.
"I'll continue to monitor the environment and if I think it's time to have that conversation again, I'll have it," she said.
"What I don't want to see is the ACT being a place where serious organised criminals, including OMCGs, can travel to Canberra to undertake their serious criminal activity."
While she was worried about violent behaviour in the territory, Assistant Commissioner Saunders said her biggest concerns stemmed from the groups' links to organised crime nationally and internationally.
Police knew of direct links between Canberra bikie group members and serious organised crime in south-east Asia, she said.
She also defended the exclusion of bikie violence as a priority in the latest ACT government ministerial direction, saying targeting serious organised crime was "bread and butter" policing.