On Monday two homes in Auburn and Arncliffe were peppered by gunfire, followed by a shootout between the occupants of two cars and, later, shots were fired into the bedroom of a house in Bankstown where a woman and her four children were sleeping.
In the past six months there have been almost 50 shootings, killing four men, wounding another four and hitting homes and businesses.
Only one charge directly related to the attacks has been laid.
A 25-year-old man was arrested in Perth on Thursday and charged with the murder of Lone Wolf bikie Neal Todorovski, who was gunned down in the southern suburb of Sans Souci on January 4.
While many of the shootings are not related, some have involved rival bikie clubs and Middle Eastern Crime gangs, and police believe the latest spate may be linked to a narcotics turf war. But investigators have run against a wall of silence.
Assistant Commissioner Frank Mennilli, commander of the South-West Metropolitan Police Region, said it was clear that not all those involved were co-operating.
"It's frustrating to us that some members of the community are involved and clearly know what has occurred but have chosen not to cooperate," he said.
"They are not only letting their community down but in some cases committing a criminal offence. These criminals are using firearms, putting the rest of the community at risk."
Acting Police Commissioner Nick Kaldas said new laws to force witnesses to speak might be needed.
He said he had discussed with the New South Wales state government the possibility of creating a new offence for witnesses failing to co-operate with a police investigation.
"I'm not sure if legislation can fix that easily, but it's certainly something we are very open to and would have a look at," he said. "We need victims and witnesses to come forward and co-operate with police - that's essential - and we need people who know about guns in our community to tell us where those gunsare so we can get them off thestreet."
Kaldas has set up an operation to boost investigations and increase patrols, using aircraft and pulling in extra officers from the public order and riot squad, and the dog, gangs and Middle Eastern organised crime squads. A major thrust will be to get guns off the street.
Most are believed to have been stolen from legitimate owners, many of whom had been careless. An Australian Institute of Criminology study found only 60 per cent of gun owners reporting theft in 2008-09 had correctly stored their weapons.
Despite firearms registers and seizures of thousands of weapons a year, there is no real figure for the number of weapons in the country, or how many are circulating illegally.
Estimates of guns registered across Australia range from about 2.5 million to 4.3 million, while some reports claim up to 500,000 weapons may be held illegally.
