NEW YORK (CBSNewYork) — The NYPD and the MTA are searching for the owner of a dog that was seen on video attacking a woman on the subway.

It happened around 3 p.m. Friday on the 4 train approaching Wall Street.

“I am as outraged as anyone when I saw that,” MTA Chairman Joe Lhota said Wednesday.

Tahysi Kyng, who recorded the video, said it began when the dog’s owner had the pit bull sit on the seat next to the woman.

“She’s like, ‘the dog don’t belong on the seat,'” said Kyng. “He’s like, ‘I’m not moving my dog.'”

“She pushes it like, ‘What is this dog doing on the chair?’ And he’s like, ‘Do not push my dog’ and she does it one more time and he starts swinging,” said witness Denise Leon,

Witnesses said the woman and the dog’s owner began arguing with the dog in between the two of them.

“He’s jumping on her but she moves back. That’s when he catches hold of her shoe and he was not letting it go,” Leon said.

The pit bull continued tugging on her shoe, his jaw tightly clenched. Eventually, the owner was able to pull the dog off. He then slams the woman’s shoe on the ground towards her.

“He never told the dog to let her go at all,” said Kyng.

“Big dogs are not supposed to be on the train,” Leon said. “I just wanted to know if she was OK.”

Kyng said the conductor made everyone get off the train at the next stop.

The MTA allows dogs on the subway but they must be contained to a carrying case or a licensed service animal that’s harnessed or leashed.

“There’s no reason in the world why that dog was allowed — one, on board, down to the platform, on the train, but let alone harassing one of my passengers,” Lhota said.

The NYPD and transit employees are responsible for enforcing the regulations, but riders have captured many instances where animals easily got on board without detection.

“It’s not even like a retriever or lab that’s helping a blind person. I don’t even know how a pit bull gets on the train,” one person said.

“Lack of police enforcement at the station,” added another.

“I know the NYPD is focused on that now. I also know that our employees are aware of what the rules are,” said Lhota.

In 2017, police issued 85 summonses to riders for having an unauthorized animal on a subway or bus. So far this year, 20 riders have been busted. The penalty? A $25 fine, which some might say isn’t much of a deterrent.

The NYPD said it has been in contact with the woman who was attacked but are still trying to track down the dog and its owner.

Lhota said riders also play a key role in enforcement and should follow the rule: “If you see something, say something.”