Georgia police are warning drivers -- especially women -- to call 911 and verify whether a traffic stop is legitimate after two women were sexually assaulted by a man pretending to be a law enforcement officer.

Investigators are trying to determine whether the same man is responsible in the attacks, which happened hours apart on Friday in Atlanta and Cobb County, Atlanta police spokesman Carlos Campos said.

The first incident happened about 1 a.m. Friday in northwest Atlanta, where a 25-year-old woman pulled over for a car with a flashing lights bar.

Less than four hours later, a woman driving saw what she thought was a police officer making a traffic stop, Cobb County police Sgt. Wayne Delk previously told The Atlanta Journal-Constitution.

The man approached the car and asked to see the woman’s driver’s license. But when she reached for it, the man grabbed her collar and opened her door. She told police she thought she was being searched, Delk said.

“Instead, he began to grope and sexually assault the victim as she sat in her seat,” Delk said. “After a brief time, he stopped and let her leave the scene.”

The outfit worn by the man, who was described in both incidents as more than 6 feet tall, didn’t match any law enforcement uniform in the area. He drove an unknown make and model car with a light bar on top of it, police said.

The suspect is believed to be about 30 years old, with an average build, and short, dark brown hair worn in a buzz cut. His face is unshaven.

"Right now, he’s a menace to any person driving out there in the hours of darkness who can’t recognize if that’s a real police officer or not," Delk said.