Chicago Police said nine more food trucks and street vendors were targeted by armed robbery groups within hours Monday

CHICAGO (WLS) — the same group of men are behind the crime.

Several of Monday's robberies occurred just minutes apart. Chicago Police say there have been at least 20 incidents since early April, mostly on the South and West sides.

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Monday's armed robberies occurred primarily in the Garfield Park, Near West Side and North Lawndale areas at the following places and times:

Police said the group of men were aged between 16 and 21, and were wearing black ski masks and black clothes. Police said they were armed with guns. Police believe the vehicle they used for the crime was an older black Chrysler 300 with tinted windows and a shattered rear passenger window.

If you have information about this incident, contact Area Four detectives at 312-746-8253.