A police crime gangs taskforce is investigating shootings outside houses in Adelaide's north and west overnight which are believed to be linked.
The houses at Enfield and Seaton are about ten kilometres from each other and one of them was also targetted in a shooting early on Sunday morning.
Police were called to a house on Learmonth Terrace at Enfield about 2:30am after gunshots woke neighbours.
Bullet holes were found in windows and a garage door but nobody was home.
About 45 minutes later, two shots were fired into a front window at a property in Pedlar Street at Seaton.
Residents were out at the time but were inside three nights ago when shots were fired at the screen door of the house.
Police say more than one gun was used in the shootings.
The Enfield property is a former residence of bikie gang leader Vincenzo Focarelli but Acting Detective Superintendent Kym Hand says police are treating that as a coincidence.
"There's no evidence at this stage that is any way involved," he said.
"There is more than one scenario possible at play here. Crime Gangs Taskforce is being involved because Operation Alpha has enabled us to pull together a large amount of intelligence which can assist any investigation of this type.
"It is of concern that there are people in our community that will resort to the use of firearms and violence in this manner."
Police say a car was seen leaving the house at Enfield but have not provided any further details.
A neighbour says there has been trouble in the street before.
"People with firearms around the neighbour. It's not safe to, it's not safe for people," he said.
"If you hear a noise today you jump immediately."