Police have arrested four men and seized 18 motorbikes during a series of raids linked to a gathering of up to 200 people at Mayfield last month.
Officers executed search warrants at homes in Fletcher, Wallsend, Lambton, North Lambton, Toronto and Fullerton Cove on Tuesday as part of Operation Horizon.
Police allege they found 18 motorbikes, as well as helmets, clothing and electronic devices, during the searches.
Four men, aged 18, 19 and two aged 21, were arrested and taken to Waratah Police Station.
The operation was established after police were called to a park on Ingall Street, Mayfield, about 1pm on Sunday, June 14, following reports of a large gathering.
Police said between 150 and 200 people were in the park when officers arrived, while another 30 to 40 people were riding unregistered trail bikes through the parkland and on surrounding streets.
Nearby roads were closed and traffic was diverted because of safety concerns.
An 18-year-old man arrested at Adamstown was charged with six offences, including riot, participating with three or more people in violence causing fear, property damage, dangerous driving and driving while unlicensed.
He was also charged with contravening a prohibition or restriction contained in an apprehended violence order.
The man was initially refused bail but was granted strict conditional bail when he appeared in Bail Division Court 2 on Tuesday. He is due to appear in Newcastle Local Court on Thursday, July 23.
A 19-year-old man arrested at Toronto was charged with seven offences, including riot, property damage, dangerous driving, driving while unlicensed, assault with intent to rob in company and breaching bail.
He was refused bail and was due to appear in Bail Division Court 2 on Wednesday.
One of the 21-year-old men, arrested at Fullerton Cove, was charged with seven offences, including riot, property damage, dangerous driving and driving while disqualified.
He was also charged with intimidating a police officer in the execution of their duty and failing to comply with a direction under a digital evidence access order.
He was refused bail and was due to appear in Bail Division Court 2 on Wednesday.
The second 21-year-old man, arrested at Lambton, was charged with five offences, including riot, property damage, dangerous driving and driving while unlicensed.
He was granted strict conditional bail in Bail Division Court 2 on Tuesday and is due to appear in Newcastle Local Court on Thursday, July 30.
Four other men were arrested and charged last month as part of the same investigation. Their matters remain before the courts.
Police have now seized 25 unregistered motorbikes under Operation Horizon.
Investigations are continuing.
