Mass Transit detectives are asking for the public's help with identifying a man they said robbed another passenger on a CTA bus last month on the city's Southwest Side.

The robbery happened shortly after 5 p.m. on June 28 in the 3800 block of South Archer Avenue.

The suspect allegedly took the passenger's cellphone forcefully and fled from the bus.  

He is described as an African American man between 25 and 30 years of age, standing between 5-feet-8 and 5-feet-11, weighing between 175 and 180 pounds, with a beard.

At the time of the robbery, he was wearing a black short-sleeved shirt with white stripes on the front of the shirt and sleeves, grey colored jeans with rips on the legs, and colored Air Jordan 2 gym shoes.

Anyone with information is asked to contact Mass Transit Detectives at 312-745-4447 or submit an anonymous tip at CPDTIP.com, using reference number JJ-312821.