Angier, N.C. — Harnett County authorities said Wednesday that they are investigating reports that someone impersonating a law enforcement officer followed at least two vehicles last weekend.

A Fuquay-Varina woman told deputies that she was driving on Chalybeate Road in northwest Harnett County at about 6:45 p.m. Saturday when a dark-colored vehicle turned on red and blue flashing lights and began following her as she turned on to Baptist Grove Road. The unidentified woman called her boyfriend and stayed on the phone with him as she drove to his home, and the trailing vehicle turned off the flashing lights and sped off when she pulled into his driveway, authorities said.

Less than three hours later, a second woman said a vehicle with flashing lights began following her at the same intersection but never tried to pull her over.

A man told authorities that he was driving near the intersection of Oakridge River and Cokesbury roads in the same part of the county at about 8 p.m. Sunday when he spotted a vehicle turning red and blue flashing lights on and off. The unidentified man said he turned around in the intersection to get a better look at the vehicle, which then sped away.

The vehicle is described as dark blue or green, resembling an unmarked police cruiser. The flashing lights were on the car's grill and atop the dashboard, authorities said.

Harnett County Sheriff Larry Rollins said his deputies weren't in the area when any of the three cases were reported, so whoever used the emergency lights is an impostor.

"There's high alert in the area. You can believe it," Rollins said.

A Harnett County Sheriff's Office incident report indicates that someone impersonating an officer robbed Christopher Lassiter, 21, a Campbell University student, on Oct. 20 after stopping him on U.S. Highway 401 near Rawls Church Road, which is in the same part of the county as last weekend's incidents.

Rollins said he has talked with Johnston County Sheriff Steve Bizzell about similar "blue-light bandit" cases in that county, but he's uncertain if the cases are linked.

Five incidents of a police impersonator following drivers were reported in Johnston County between late March and early May. Three of those people were robbed.

Other cases were reported in Cumberland and Durham counties last spring.

"The vehicles could be similar, it sounds like, in Johnston County, so we could be dealing with the same guy," Rollins said.

Authorities said anyone who is pulled over by a car with flashing lights can call 911 to check whether a deputy or police officer is involved in the traffic stop. Drivers also should turn on their hazard lights and stop in well-lit areas.

"We want the community to be on alert for this and have awareness of it, but it makes our job harder," Rollins said, adding that he hopes the "blue-light bandit" slips up and pulls over the wrong person.

"I hope it's one of my undercover deputies. They'll be prepared," he said.