The crime happened two days in a row in the Heart of Chicago neighborhood.
Police said that just before 7 a.m. a man, who was standing across the street, stuck his tongue out to the victims and tried to get their attention while performing lude acts.
The incidents happened on May 1 and May 2 in the 2000-block of West 23rd Street, according to police.
The suspect was described to be heavy set man with short dark hair and wearing a red jacket.
Anyone with information is urged to call Chicago police.
The age of the victims was not released.
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