A Hells Angels member was buying a motorcycle at the Essex Street shop on Saturday when a Pagan reportedly told him "this is Pagan territory," according to Rochelle Park police.
They began to argue, after which several members of each gang showed up "to support their member," according to a police report.
"The situation was de-escalated by a large police presence," the report said.
Rochelle Park police thanked their colleagues from Lodi, Maywood, Saddle Brook, the Bergen County Sheriff's Office and the Bergen County Regional SWAT team, who all responded.
"Intelligence obtained after the incident indicates tensions between the two motorcycle gangs [are] going to escalate," they added.
"You're going to see a lot more incidents between these [two]," one officer said. "They're fighting for territory."
Click here to follow Daily Voice Northern Valley and receive free news updates.