CHICAGO (WLS) -- An off-duty Chicago police officer is being credited with helping to nab two suspects who robbed and attacked a man Sunday afternoon in the Lakeview neighborhood.A 63-year-old man was walking on the sidewalk in the 1000 block of W. Barry Street at 3 p.m. when a man approached him and punched him in the face, according to Chicago police. The offender then pulled out a gun and a second man approached as the victim shouted for help.The two began hitting the victim with the gun and their fists as they searched the victim's clothes for valuables.An off-duty Chicago police officer heard the man's shouts for help. The officer pulled out his service weapon and confronted the armed robbers, who fled with the victim's wallet.The officer called in the location of the crime and descriptions of the suspects. Responding officers saw two men matching the descriptions, and they were arrested after a brief foot chase. A weapon was recovered, police say.David Shabazz, 20, of the 5400 block of S. Aberdeen, has been charged with one count of felony aggravated battery to a senior, one count of felony armed robbery, one count of felony unlawful use of a weapon.Juwan Askew, 18, of the 200 block of W. Garfield Blvd, was charged with one count of felony aggravated battery to a senior, one count of felony armed robbery and one misdemeanor count of resisting arrest.Public safety officers at the Illinois Masonic Medical Center say they helped too, finding one of the men hiding under a car in their parking garage.One woman, who was too nervous to give her name, says she's been concerned about the growing number of robberies in the Wrigleyville and Boystown neighborhoods near CTA stops. There were five on Saturday alone, including two people robbed at gunpoint at her stop - Fullerton."The assailants - alleged assailants - jumped back on the train after robbing people," she said.Police have not confirmed if these two men are also responsible for those five robberies. But they say detectives are looking into the connection and will file more charges if necessary.