Calgary police are seeking help from the public in locating a man believed to be posing as an officer.

There were two incidents early this morning when a silver sedan, using red and blue lights attached to the dashboard, tried to pull over motorists.

In the first case, a woman driving along Palliser Drive S.W. noticed she was being followed around 2:30 a.m. MT.

The vehicle activated red and blue lights, so she pulled over and waited. She became suspicious after the driver, who approached after a period of time, shone a flashlight in her eyes — so she drove away and called 911.

A short time later, a sedan pulled over another car with flashing lights, but drove away before anyone actually approached the male driver.

The man in the sedan is described as white, about five feet seven inches tall and wearing green sweatpants.

Calgary police were unable to locate the vehicle. Officials say while the motive behind the incidents isn't known, it is a serious offence to impersonate an officer.