SPARTA, N.J. (CBS 2) — Some brazen crimes have left frayed nerves among residents in an upscale New Jersey community, with police advising residents to lock their doors.

Three smash-in burglaries in the area have left Sparta residents on edge.

READ MORE: Gov. Cuomo Signs Gender Recognition Act, Expanding Protections For Transgender And Non-Binary New Yorkers

“It’s scary, you know?” resident Howard Perrine said. “You feel violated.”

Two of the burglaries happened Thursday night – and all three involved million-dollar homes – ramping up concern in the normally quiet town.

“It’s very upsetting. You worry about your family, number one, and after that, what they can take,” resident Bob Einreinhofer said.

Local police say the crooks smash in the doors, pull alarm systems off the walls and cut phone lines. They say the sophisticated tactics show the burglars know what they’re doing.

In one of the cases Thursday night, a woman was at home, asleep in her bed. The thieves broke in, frightening her badly, before escaping into the night.

READ MORE: East Flatbush Hit-And-Run Victim In Critical Condition; Neighbor Says Cars Speed Through Intersection 'All The Time'

“I’ve never seen burglaries committed with such brazen acts of crashing through the door when the residents are home,” Sparta Township Police Lt. Joseph Schetting said.

Police say the smash-in jobs look like they were done by the same group of perpetrators – at least two men, they believe – and may be related to burglaries in other northern New Jersey towns, though they wouldn’t say which ones.

“We believe this is an organized burglary ring,” Lt. Schetting said.

In each case, police said, the thieves made off with cash and jewels.

“As we all know, gold is through the roof, so it’s a hot commodity right now,” Lt. Schetting said.

Police are urging residents to keep their alarms on, even when they are home, and to call if they see anything suspicious.

MORE NEWS: Woman Struck And Killed While Pushing Baby In Stroller In Queens

Lt. Schetting said in his 22 years on the force, he has never seen such brazen crimes in Sparta.