Four men and two teenage boys have been charged after police allegedly caught two members of the group travelling in a taxi with loaded firearms.
The arrests are part of an ongoing investigation into a shooting in Sydney's northwest in November where police allege two men fired shots and a stun grenade into a Tallawong home, in northwest Sydney.
A 19-year-old was arrested and charged for his role in the incident as police continue to home in on other members of the allegedly violent group.
Police on Monday said they arrested a 16-year-old boy and a 20-year-old man in Old Toongabbie in Sydney's west.
The pair, also believed by police to have taken part in the Tallawong shooting, were travelling in a taxi and allegedly in possession of two loaded firearms and a dedicated encrypted criminal communication device.
NSW Police Detective Acting Superintendent Brad Abdy said the men were on their way to commit a serious violent act.
"They were stopped by members of our highway patrol, and they were actually in a taxi," he told reporters on Tuesday.
"They were arrested shortly after they ran ... we believe they were on their way to commit a further serious act involving firearms."
Later on Monday, a 25-year-old man was arrested in Guildford where police allege he was found in possession of two mobile phones, one of which was also an encrypted communication device.
He was refused bail and is set to appear before a Sydney court on Tuesday.
Further searches at Rouse Hill in northwest Sydney uncovered a trove of four stolen vehicles, five firearms, thousands of rounds of high-calibre ammunition, fake number plates and two ballistic vests.
As police were on scene, three males - two men aged 18 and 23, and a 17-year-old boy - ran from the property but were promptly arrested.
The 16-year-old boy and 20-year-old man found travelling in a car with loaded firearms have been hit with a slew of charges including multiple firearm-related offences and participating in criminal group activity.
Both have been refused bail and are set to appear before a Sydney court on Tuesday.
The three men who fled during the police search of a Rouse Hill property have also been charged with similar offences.
All three were refused bail to appear before a Sydney court later on Tuesday.
"This seizure certainly hinders that group and dismantles that criminal syndicate," Supt Abdy said.
Police believe the group operate as a team contracted to carry out offences on behalf of others.
