CHICAGO (CBS) — Police said they have made some arrests following a string of attacks on Chicago Transit Authority trains.

Three teenagers were charged after a man was punched and robbed on a Brown Line train near the Belmont stop on Wednesday night.

Police said a 55-year-old man said he was on a train when a group of assailants took his personal property and punched him.

Officers were told there was a girl who was moving from car to car as they investigated. They found her hiding under the seats with the victim’s property, police said.

The girl, 16, was charged with one count of theft. Two others – a 13-year-old girl and a 15-year-old boy – were also arrested and charged with obstructing identification.

Another teen is charged with several felonies in connection with two robberies on the Red Line subway in recent days.

One attack happened on Sunday around 3:40 a.m. near the Harrison station. An assailant attacked 37-year-old man and robbed him, police said.

There was also an attack at 5:40 p.m. Tuesday near the Chicago Avenue stop. In that instance, another 61-year-old man was punched in the face and robbed by a male juvenile, police said.

One boy was charged in both of those cases. He was charged with two counts of robbery, and one count each of aggravated battery to someone over 60, aggravated battery causing great bodily harm, and aggravated battery to a peace officer.

There have also been attacks in recent days at the Grand, Lake, and Roosevelt stops on the Red Line. A pregnant woman was the victim in the Roosevelt attack.

And on Thursday morning, a man was stabbed in a quarrel near the Cicero Avenue stop on the Blue Line. The assailant in that case remained on the loose Thursday night.