The incident happened on a Red Line train near the Granville Station at about 10:40 p.m. on November 13.
The men seen in the photos allegedly tried to take a passenger's wallet and backpack; when he refused, one of the suspects began to punch the victim.
One suspect is seen wearing a hoodie with "Chicago-The Windy City" emblem on the chest.
The other suspect was wearing a black Nike hooded sweatshirt and a black ski mask.
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