A Chicago police officer followed a man off a CTA subway train after he was seen walking between train cars, and then shot the man twice during a struggle inside a busy downtown Red Line station during the Friday afternoon rush hour, according to police.

Two officers were taken off the street pending an investigation of the encounter, part of which was captured on video that Mayor Lori Lightfoot called “extremely disturbing” and which police officials suggested could be part of a criminal probe.

It all happened just hours after interim Chicago Police Supt. Charlie Beck joined Lightfoot and CTA president Dorval Carter to announce a new security plan for the mass transit system, which has seen a rash of shootings in recent weeks.

Lightfoot said in a Friday evening tweet that “with the strong caveat that one perspective does not depict the entirety of the incident, the video is extremely disturbing and the actions by these officers are deeply concerning.”

The sequence started shortly after 4 p.m., when two officers assigned to CPD’s Mass Transit Unit saw a man “jumping from train to train,” police said. They followed him off the train and approached him in the station, still underground, Deputy Supt. Barbara West said.

Both officers used stun guns as they tried to arrest him, then “at some point during the incident, one of the officers discharged a weapon, striking the subject twice,” West said.

Shortly after the shooting, a two-minute cellphone video began circulating on social media, showing both officers on top of the man, struggling with him on the ground near an escalator as they try to handcuff him.

At one point in the video, an officer appears to use pepper spray near the man’s face, and a deployed stun gun rests on the ground nearby.

One of the officers yells, “Give me your hands! Give me your hands!” before shouting, “Stop resisting!” seven times in a row.

The man eventually gets to his feet, stumbling backward, and the same officer can be heard yelling “shoot him” to the other officer.

The second officer draws her weapon and, with the man just feet away, a gunshot is heard.

The man runs up the escalator, and the officers follow. A second gunshot is heard off screen.

Another video of the minutes leading up to the gunfire shows the officers wrestling the man to the ground and using their stun gun on him multiple times. Dozens of commuters walk past directly past the chaos before heading up the escalator.

This is the two minutes leading up to the previous video. (Twitter won't let me upload it all at once.) pic.twitter.com/rkWrIfSkpE — The Unaffiliated Critic (@FreeRangeCritic) February 28, 2020

West, speaking outside the Grand Red Line station at Grand Avenue and State Street, said she had been in touch with Beck, “and at this point we’re both extremely concerned and have significant questions about this incident.”

The man who was shot made it through surgery Thursday evening at Northwestern Memorial Hospital, and though he remained critical, his condition was stabilized, West said.

Lightfoot said she supported Beck’s decision to consult the Cook County state’s attorney’s office on the matter, which West told reporters at the scene Friday night was “due to the potential criminal nature of this incident.”

The mayor, who served two terms on the Chicago Police Board under former Mayor Rahm Emanuel, vowed “full transparency and accountability ... to ensure the public gains a complete picture of what happened.”

West noted that moving between train cars is “in violation of a city ordinance.” She said she was unsure if the officers’ body cameras were activated.

Asked if a weapon was recovered from the man, a police spokesman said he didn’t know.

Investigators from the Civilian Office of Police Accountability were at the scene Friday night. Anyone with information about the shooting is asked to contact the agency at (312) 746-3609.

The officers, per department policy, were taken off patrol and given paid administrative duties while the investigation unfolds.

At street level outside the station Friday evening, police taped off one block in each direction, making for an eerily quiet few blocks in the usually bustling area.

Hours earlier, Lightfoot and Beck had appeared at the Roosevelt CTA station announcing a bolstered police presence on the CTA in response to a series of violent incidents on trains and platforms over the last month. The new plan includes adding 50 officers to the Mass Transit Unit, assigning four detectives exclusively to CTA crimes and building a strategic deployment center.

The third tragedy in a month struck the transit system when a man was shot to death and two other people were wounded early Monday in the tunnel connecting the downtown Jackson Red and Blue lines.

Earlier this month, a musician was stabbed on the busy Jackson Red Line platform. The next day, a man was shot while exiting a Blue Line train at the UIC-Halsted station. Suspects were taken into custody in both incidents.