The attack happened around 9:15 a.m. Tuesday, Dec. 12 near the fare gates for the Market-Frankford Line, transit officials said.
Investigators believe the suspect may have an eastbound Market-Frankford Line train, and SEPTA police said they are working with authorities in Upper Darby and Philadelphia to locate him.
Commuters should expect "residual delays" on the Market-Frankford Line Tuesday morning due to police activity, they added.
Anyone who can identify the pictured suspect is asked to call SEPTA Transit Police at (215) 580-8111.
This is a developing story. Check back for more.
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