But Gangs Squad commander Arthur Katsogiannis said the tit-for-tat violence was part of a dispute between individual bikies and not a war between the clubs.
Superintendent Katsogiannis and Middle Eastern Organised Crime Squad commander Deborah Wallace yesterday called for a end to the violence after shootings near the Ibrahim family home in Merrylands and at Ermington over the weekend.
Among possible motives for the violence was a number of recent defections between the clubs, known as "patching over", Supt Katsogiannis said.
"If this was a full scale war between the Nomads and the Hells Angels you would not have the shootings isolated at one particular area, they would be right around the metropolitan area and around the state," he said.
"It is a conflict between two or three individuals who are part of those gangs, and the conflict is solely between themselves and we're trying to resolve that."
Police have linked eight shootings since last Thursday to the dispute, including one inNorthmead where an innocent woman's house was sprayed with bullets as she slept.
In the last attack, a Merrylands home belonging to a member of the Ibrahim family was shot at on Saturday about 8.45pm. A black four-wheel drive was seen leaving the area after shots were fired, but no one was injured and there was no damage to the house.
In the later incident, police were called to a house at Ermington about 12.05am yesterday after the owner came home and discovered damage to the front of the house.
Police believe the damage to a wall and window was caused by a bullet. No one was in the house at the time.
Strike Force Felix, established to investigate the shootings, has made "significant inroads" about the identity of those involved and the cause of the dispute, Supt Katsogiannis said. "We want to reassure the public that we are doing everything possible."