A 34-year-old man from Kaikohe was charged with alleged unlawful possession of shotgun ammunition but the matter was resolved at his first court appearance.
The police operation has so far also seized 41g of methamphetamine and about $1140 in cash.
The 11 arrested men are aged between 15 and 55 years.
Detective Senior Sergeant Mark Dalzell said police were continuing to investigate four incidents, three involving firearms, in the Kaikohe area since March 13.
Police believed the incidents were linked and all involved the Tribesmen and Killer Beez gangs.
In the first reported incident, a man was allegedly violently assaulted by a group of men on Broadway about 1.50pm on Monday.
He suffered head and other injuries and was taken first to Bay of Islands Hospital, then transferred to Whangārei Hospital.
Police later stopped a vehicle thought to be connected to the assault as it travelled north on State Highway 10, south of Kerikeri, and took its occupants to Kaikohe police station.
On Tuesday a man was shot in the leg about 12.30pm on Aerodrome Rd, off Mangakahia Rd, south of Kaikohe. He was taken to Whangārei Hospital.
Dalzell said police weren't ruling out further arrests in relation to the "extremely serious" events.
He said the incidents were not random acts of violence but involved ongoing tensions between the two gangs.
