A brazen armed robber hit five SuperAmerica and Walgreens stores in south Minneapolis in rapid fashion before dawn Tuesday, an unusual spree that police said is a high-priority case heading into the new year.

The holdups started at 4 a.m. at a SuperAmerica convenience store at 6000 Portland Av. S. and ended at another SuperAmerica at 4320 E. Lake St. at 6:30 a.m. Cash was taken from each store and prescription drugs were also taken from a 24-hour Walgreens at 2426 Hennepin Av. S.

Nobody was injured, but police are concerned about the potential for violence because the suspect had a gun, said police spokesman John Elder.

As the robberies were reported to police, the department's watch commander quickly noticed that the robber was moving east. Officers then called businesses in the suspect's possible path to warn them, Elder said.

Squads from other city precincts also mobilized, while other officers helped to canvass and take reports from the crime scenes, he said.

The suspect also robbed Super­America stores at 2501 Hennepin Av. S. and 2200 Lyndale Av. S. There hasn't been any similar robbery pattern at the University of Minnesota, in St. Paul or elsewhere in the metro area, Elder said.

At each store, the suspect usually walked up to the cashier, brandished a black semiautomatic handgun and calmly made his demands, Elder said. He didn't scream any threats, and there was no indication he was under the influence of alcohol or drugs.

There would have been few customers in the stores at that time of day, and officers are trying to find witnesses, Elder said.

Authorities have released surveillance images taken at the Lake Street SuperAmerica.

The suspect is described as black, heavyset, 20 to 30 years old, and dressed in black with a black knit hat face mask covering his face. In at least two of the robberies, he was wearing glasses.

Anyone with information is asked to call police at 612-673-3856 or the tip line at 612-692-8477.

Police also said that there was an armed robbery of a business about 10 a.m. Tuesday at W. Lake Street and Knox Avenue S., but that the suspect's description was different from the one in the earlier robberies.

david.chanen@startribune.com • 612-673-4465 paul.walsh@startribune.com • 612-673-4482