UPDATED 09/07/11 6:54 a.m.
CHICAGO (CBS) -- A scary warning has been issued for people who live all around the city's Northwest Side.
As CBS 2's Susanna Song reports, police advise people to be careful in alleys, or if they have their garages open.
In all the incidents, several robbers come up to the victims in open garages or alleys, and rob them of their wallets, money and cell phones at gunpoint.
LISTEN: WBBM Newsradio's Mike Krauser reports
Police say there have been at least seven stick-ups in recent days, all in the early to mid-evening hours in the past few days. It appears the robbers are trolling the alleys looking for their victims.
The Logan Square, Irving Park, Albany Park, Belmont-Cragin and Edgebrook neighborhoods have been affected.
Specifically, the robberies happened:
--At 7:53 p.m. Friday in the 2200 block of West Fullerton Avenue;
--At 7:55 p.m. Friday in the 2200 block of West Medill Avenue;
--At 4:55 p.m. Sunday in the 3900 block of North Troy Street;
--At 5:15 p.m. Sunday in the 3700 block of West Montrose Avenue;
--At 5:55 p.m. Sunday in the 6200 block of North Leona Avenue;
--At 6 p.m. Sunday in the 2400 block of North Maplewood Avenue;
--At 9:05 p.m. Sunday in the 2100 block of North Monitor Avenue.
One neighbor in Logan Square, Ricardo Robles, said he was surprised by the robberies. But he also said there are building security concerns that could make more robberies likely.
"Actually, the back door is right by the alley, and there's an entrance from the alley where anyone can be, like, under the porch, or in between the building and the garage," Robles said. "We're definitely going to have to make that much safer, especially for the tenants."
The suspects in the robberies are described as three African-American men between the ages of 20 and 35, standing 5 feet 7 to 6 feet 2 inches tall and weighing between 160 and 190 pounds. They all wore different-colored baseball caps, and at least one of them is armed with a small-caliber handgun, police said.
In one incident, they escaped what was believed to be a gray Nissan, and in another, an unspecified gray four-door vehicle, police said.
Police advise neighbors to report suspicious people and be aware of the situation, pay special attention to loiterers, and lock all garage doors and windows.
Anyone with information is asked to call Grand Central Area police detectives at (312) 746-8362.
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