CHICAGO (WLS) -- Chicago police have issued an alert after a female student was groped on the ramp leading to the eastbound Blue Line train platform at Cicero on Monday morning.Police say the victim was followed by the offender, who continually yelled at her. The offender caught up to the victim at the platform and grabbed her from behind, inappropriately touching her.As the victim attempted to pull away, she fell to the ground, causing her wallet to fall on the platform. The offender grabbed the wallet and fled from the station.The offender is described as a male black, 20-28 years of age, 5'6-5'8, with a thin build. He was wearing a hooded jacket which was light blue on the top area and black on the lower area, dark jeans and white colored gym shoes.Police are asking the public to call 911 to report any suspicious activity. They also urge riders to walk in pairs and stay in well lit and populated areas.