CHICAGO (CBS) — Police on Tuesday issued a community alert after a man was robbed and stabbed on a CTA Purple Line train downtown.

The robbery happened at 7:18 p.m. Monday on a Chicago Transit Authority Purple Line train headed toward the Adams-Wabash station.

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Police said the assailant came up to the victim, displayed a knife, and demanded the victim’s cellphone. The victim handed over his cellphone, and the suspect then demanded his passcode and stabbed him with a knife, police said.

Police released photos of the assailant approaching the suspect with a knife.

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Purple Line Robbery, Stabbing

(Credit: Chicago Police)

The assailant is described as African-American, between 30 and 40 years old, standing 5 feet 7 to 5 feet 9 inches tall with a medium complexion.

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Anyone with information about the suspect is asked to call Mass Transit Detective Ray Verta at (312) 745-4443 or (773) 664-4880, or by email at Raymond.verta@chicagopolice.org. The reference number for the case is RD#JE-211014.