A shocking video posted on Instagram shows a pit bull attacking a woman on the subway and refusing to let go even as several people tried to pull the dog away.

The video shows the pooch chomping down on a woman’s shoe for several seconds as straphangers yell at the animal’s handler.

“Get the dog off of her!” yells one woman.

“Call the police!” another man screams.

The train descends into chaos as riders try to get away from the dog. A man sitting next to the woman with her shoe in the dog’s mouth pulls hard on her leg to try to shake the beast off.

The dog finally releases near the end of the video and the animal’s handler tries to get it back into a crate while other riders continue to scream at him.

MTA officials, who didn’t know where and when the incident happened, called the video disturbing.

“Our rules require non-service animals to be kept inside containers and not disturbing other passengers,” said MTA spokesman Shams Tarek.

“What’s happening in this video is disturbing and a clear violation of our rules. We flagged this video for NYPD, which is responsible for enforcing Transit rules.”