CHICAGO (CBS) — Police on Wednesday issued a warning about three more robberies downtown – in which these times, multiple young suspects have made off with victims’ Divvy bikes.

In each incident, the robbers approach the victims and demand the bikes while implying they are armed with a weapon.

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The incidents happened at the following times and locations:

• At 7 p.m. Saturday, Aug. 21, in the 0-99 block of South Michigan Avenue
• Half an hour later on the same block;
• At 6 p.m. Sunday, Aug. 22, in the 200 block of East Randolph Drive.

The suspects are described as both males and females between the ages of 15 and 25.

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

These latest incidents come amid a growing concern about robberies and attacks committed by large groups of young people in the downtown area over recent weeks.

This past Thursday night, David Osorio was walking down the Huron Street near Franklin Street in River North when a group of teens attacked him, knocking him out and breaking his car windshield. Osorio told CBS 2’s Steven Graves he is hoping any nearby surveillance camera caught something, because he blacked out after hitting the ground.

Police have warned of similar random attacks just to the south in the Loop, where the Divvy bike robberies also occurred.

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A woman who was brutally beaten late Saturday night was one of the victims in a string of five attacks over three days, each carried out by groups of teens.

CBS 2 Chicago Staff