Police issued a warning to Northwest Side businesses about an armed robber who stole money from registers at three locations this week. View Full Caption Getty Images/File Photo

CHICAGO — Police issued a warning to Northwest Side businesses about an armed robber who stole money from registers at three locations this week.

The incidents occurred at the following locations and times, according to an alert from the Jefferson Park police district:

• 5200 block of North Milwaukee Avenue at 8:05 p.m. Sunday.

• 5300 block of North Milwaukee Avenue at 10:20 a.m. Monday.

• 6200 block of West Belmont Avenue at 9:04 p.m. Tuesday.

In each of the cases, the suspect entered the business and demanded money from the register while holding a black handgun.

The suspect is described as being either white or Hispanic, 30 to 42 years old, 5-foot-5 to 5-foot-10 tall, and weighing 270 to 300 pounds. During the robberies, he was wearing dark clothes.

Anyone with information is asked to call detectives at (312) 744-8263.