The first robbery took place on a train in the 1900-block of South Kedzie Avenue at about 1:50 a.m.
A 23-year-old woman said she was on a train when she was approached by two male suspects in all-black clothing, police said. The woman told police one of the suspects took out a handgun and placed it on the side of her head while demanding her personal belongings.
The suspects then fled in an unknown direction, police said. The woman was not injured.
The second robbery occurred just five minutes later on the Pink Line station platform in the 1900-block of South Kedzie Avenue.
South Loop safety meeting zeros in on CTA crime, which is up compared to last year
Two men told police that they had just gotten off a train and were on a platform when two suspects approached.
The suspects pointed guns at the victims and demanded their belongings, police said. The victims complied and some of the belongings were later recovered nearby.
The suspects were last seen running north, police said. The victims were not injured.
No one is in custody in connection with either robbery. Area 4 detectives are investigating.
There was also an armed robbery on the CTA Red Line hours later.
A 48-year-old man said he had fallen asleep on a southbound Red Line train about 4 a.m. in the 1100-block of West Bryn Mawr Avenue when an unknown male suspect woke him up, pointed a gun at him and demanded his belongings, according to CPD.
The suspect took items out of the victim's pockets and exited the train.
The victim exited the train at Clark and Division streets and reported the incident.
The man was not injured, and no one is in custody. Area Three detectives are investigating.