Officials are looking for a customer who may have witnessed a gas station robbery in the town of Burke Saturday night, officials said.

Dane County sheriff’s deputies responded around 9 p.m. to reports of an armed robbery at the BP Gas Station at 3893 Steven Drive, according to a release.

On Monday, the sheriff's office added that it was seeking a customer who arrived at the BP shortly after 9 p.m., discovered the store was closed and left. The customer is not a suspect, officials said. Investigators said the person may have unknowingly witnessed a portion of the robbery. The customer was driving a dark two-tone Chevrolet or GMC extended cab pickup truck.

A man entered the store wearing a black ski mask and displayed a silver semi-automatic handgun, police said. The man ordered the clerk to empty the cash drawer, and then left on foot with an undisclosed amount of cash.

The man is described as white, about 6 feet tall and weighs about 160 pounds.

Officials asked anyone with information about the robbery to call 608-284-6900.