Chicago police are asking for help identifying the man who stabbed a CTA passenger on a Blue Line platform over the weekend on the Near West Side.

Police said around 11:15 p.m. on Saturday, the man pulled a large knife out of his backpack while on the platform at the UIC-Halsted stop on the Blue Line, walked up to a female sitting on a bench, and stabbed her in the chest.

The man then fled the platform and headed north on Morgan Street.

Police released a surveillance image of the man, who was last seen wearing a pink beanie, gray hoodie, orange sweater, faded blue jeans, white shoes, and a gray backpack.

Anyone who recognizes him is asked to call Area 3 detectives at 312-744-8261, or to submit an anonymous tip at CPDTip.com.