A man was shot on a Red Line train in a Loop subway stop Thursday night causing commuters to scramble from the car's rear exits as police arrived, authorities and a witness said.

Emergency responders took the wounded man, 23, from the Jackson station in the 200 block of South State Street to Northwestern Memorial Hospital where his condition had stabilized, fire officials said. Police said the man was shot in his left arm and ankle about 7:50 p.m.

The victim was targeted, police said, and detectives were reviewing surveillance video from the station. The Chicago Transit Authority said the shots were fired from the platform, not inside the train.

Police said they are still looking for the shooter who fled up the subway stairs.

Andrew Lapin said he was four or five cars behind the one where the shooting took place. He said he heard gunfire and then people in the train "hit the deck.” He said people on the train seemed too scared to leave at first.

“People started streaming out the back exit as cops came so I followed them,” he said. “When I was leaving people were still cowering inside the train."

Lapin said what stuck out to him the most during the chaotic ordeal was what the conductor said after the gunshots.

“I was not expecting, after the shots, to hear the CTA operator come on the intercom to say, ’Can I help you?’” he said.

Red Line trains were being rerouted to the elevated tracks between Fullerton and Cermak, the CTA said.