FITCHBURG, Wis. -

Police said investigators don't yet know if two overnight robberies -- which occurred six hours and about a quarter-of-a-mile apart in Fitchburg -- were related.

The first robbery the Fitchburg Police Department responded to was at a pizzeria at 2980 Cahill Main at about 9 p.m. Saturday, according to a report.

Police said the suspect entered Papa Murphy's, demanded money and fled the scene. The Fitchburg police K9 unit assisted officers attempting to track the suspect but investigators said the suspect may have fled in a black four-door sedan.

Police said no weapons were displayed during the robbery and no injuries were reported.

The report described the robber as a white man, about 25 years old, wearing blue cargo-style pants, a black hoodie and a black hat.

About six hours later and a mile northeast of Papa Murphy's, another robbery was reported, this time at a convenience store.

Fitchburg officers responded to a report of a robbery at 2932 S. Fish Hatchery Road early Sunday at about 3:31 a.m.

Police said the suspect entered the Stop-N-Go store, demanded money and fled the scene.

The K9 unit from the Mt. Horeb Police Department assisted Fitchburg police, attempting to track the suspect. The report said no weapons were displayed and no injuries were reported.

Police said the suspect in the Stop-N-Go incident was described as a short-haired white man with a goatee. He was wearing faded blue jeans and a black hoodie that had "BISON" written on the front, investigators said.

In a news release Sunday morning, Chief Thomas Blatter said it was unknown if the robbery at Stop-N-Go was connected to the earlier robbery at Papa Murphy's.