More than 100 police, including PolAir, the dog squad and the riot squad, swarmed Fairfield East looking for four men who robbed a Commonwealth Bank in Chester Hill and the Rosnay Golf Club in Auburn on Friday morning.

The group had a head-on collision with a passing motorist in Tangerine Street and unsuccessfully tried to carjack two other vehicles before fleeing on foot.

Staff at the golf club reportedly thought it was a Halloween prank at first until the three men, armed with two rifles and a hammer, stole money from the till and fled in a blue sedan.

An unmarked police car that happened to be nearby initiated a pursuit but stopped when the sedan crashed. The men were chased by police on foot but managed to escape.

After a tip off that the group had taken refuge in a home on nearby Hercules Street, police locked down four streets in Fairfield East and told residents to stay indoors while heavily-armed officers swarmed the area.

However, the men were not in the house and residents were allowed back into the area by mid-afternoon.

The search was scaled back on Friday with the public warned not to approach the men, who are believed to be armed and dangerous.

Mark Malwijiw, who lives 20 metres from where the car was crashed and abandoned by the robbers, said he would be keeping a bat close to him on Friday, fearful that the gang could be hiding in the area.

"I can't believe they haven't been able to find them," he said. "They got very lucky... I reckon they have hidden in someone's backyard and will wait until the coppers are gone.

"I'm gonna hold a bat close to me.

"It's pretty scary knowing these guys are still around."

Superintendent Tony Gillam said the operation had wound down on Friday afternoon.

"Eventually, we received a call that these people were spotted in a premises here in Hercules Street," he said.

"We initiated a police response that led to operation where we put in a significant perimeter. We went into a stage of containment and trying to locate these offenders. Unfortunately, we have not been able to locate them... so we have wound down the operation."

A NSW Ambulance spokesman said paramedics treated two women, including one who was pregnant, for shock at the Chester Hill Commonwealth Bank.