By Kerri Corrado

PHILADELPHIA (CBS) — A security guard was caught on surveillance video punching a SEPTA passenger to the ground. A SEPTA spokesperson says this is a criminal investigation and they are still looking into what led up to a brutal attack on a passenger by a security guard.

Video obtained by Eyewitness News from a SEPTA surveillance camera at the Arrott Transportation Center on the Market-Frankford Line shows an Allied Universal security guard — who is contracted by SEPTA – attack a 51-year-old passenger on Tuesday afternoon.

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You can see that guard punching the man multiple times until he falls to the ground right at the fare gates.

CBS3 EXCLUSIVE: SEPTA Surveillance Cameras Capture Security Guard Brutally Attacking Passenger

A SEPTA spokesperson says they do know there was some sort of argument that turned physical.

“It appears the two were in a verbal disagreement of some type for a couple minutes before it became physical. And then the video shows that the security guard struck the man and the man fell to the ground,” SEPTA spokesperson Andrew Busch said.

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The guard fled the scene immediately after and SEPTA is working with Allied Universal and trying to interview him at this time.

The passenger was taken to Temple University Hospital and treated for non-life-threatening injuries.

Allied Universal says they are disgusted and deeply disappointed by the video, saying in a statement: “We do not tolerate aggressive or inappropriate behavior of any kind by our employees. Our highest priority is the safety and well-being of all members of the public.”

SEPTA recently announced they would continue a $1.5 million contract with Allied Universal to launch earlier this year to keep guards at several “El” stations for extra safety and security.

That’s something the transit police union says is a bad idea, and in their own statement says the incident “further illustrates the need for more SEPTA police officers on patrol, not rouge security agents assaulting passengers and creating havoc on our transit system.”

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Eyewitness News asked multiple times but SEPTA will not confirm if that guard is in police custody or not.