SYDNEY, it seems, is a city on the edge. In a call to radio station 2GB on Wednesday night, ''Wade'' described shots being fired in Guildford, a western suburb not immune to drive-bys.

There were ''15 to 20'' police only 100 metres from the Uniting Church, Wade said.

The police media unit confirmed they were investigating the reports, saying officers were looking for a late-model silver Mercedes-Benz sedan seen near Linwood Street that could help with their inquiries.

But it seems there was a much less sinister sequence of events - there were no bullets. A van had been ''deliberately and repeatedly'' backfiring in the area.

A false alarm - but the rise in gun violence this year has residents bracing for the night it will be their street in the firing line.

The shootings, one detective said, were a minefield because they involved everything from drug territory, organised crime groups and bikie turf wars to domestic disputes.

''Think of the reasons you might have arguments with family, friends and colleagues and then apply it to criminals with access to illegal guns,'' he said.

The Middle Eastern Organised Crime Squad is examining a few of the shootings in the past six months and the Herald has learnt of some loose links.

It is understood that two rival Middle Eastern crime entities are engaging in a tussle over drug-related issues - a shooting in Rockdale on December 13, in which a man was struck in the arm as he sat in his black Range Rover outside Rockdale Plaza, and the shooting into a house in Auburn on January 9 are related.

Another shooting 10 minutes later in the nearby suburb of Arncliffe is also related to that dispute and police are understood to be pursuing the same perpetrator for that attack. The victims, however, are unrelated.

There have been at least 47 shootings in the past six months and Arncliffe, Auburn, Bankstown, Fairfield, Greenacre, Merrylands and Yennora are among the suburbs that have been on the hit-list.

Many of those suburbs represent known bikie territory and tensions between the Hells Angels and Nomads outlaw motorcycle gangs were responsible for six shootings in seven days from October 27 last year.

In mid-August a tit-for-tat dispute took place in Merrylands.

Earlier this week in Wetherill Park, a woman who has also been charged with the murder last year of her partner in a domestic dispute, was at home with her two small children when two shots were fired into the property.

Police are understood to be examining Lena Kasparian's deceased partner's connections and also a suggested dispute with her former husband.

Amid this simmering tension across large tracts of Sydney's suburbs, what police fear most is the increasing likelihood victims will be struck in the crossfire.

In response to the gun crime spike this year, police went on the front foot and launched Operation Spartan, using additional resources from state crime command squads, the dog squad, Pol Air and local area commands to try to curb the gun attacks.

The offence of discharging a firearm with intent carries a maximum penalty of 25 years in jail, but if that wasn't deterrent enough, police added a weapon to their own arsenal - the use of the powerful, secretive NSW Crime Commission to compel victims and witnesses to talk.