Police said a woman found a suspicious device inside the fuel hatch of her car when she stopped at the Fred Meyer gas station at 801 Auburn Way N. around 5 p.m.
She contacted police, who called the bomb squad to the scene. Investigators transported the device to a safe area where they neutralized it.
"Test of the device showed that the device was actually an IED," Auburn police said.
Police do not believe this was a random act.
No other details surrounding the incident were immediately available, and the investigation is ongoing.