NEW YORK - The New York City Police Department now says a pit bull that attacked a woman on a city subway car last week was a service dog.

The dog's owner, Ruben Roncallo, 53, of Brooklyn, has been charged with reckless endangerment and assault.

His arrest comes days after the video went viral.

The video shot last Friday on a number 4 train shows the dog biting a woman's shoe and tugging on her foot.

Witnesses say it all started when the woman asked the owner to move his dog after it bumped into her.

When he refused, she repeatedly pushed the dog off her seat. 

The man then allegedly hit her and she hit back.

That's when the dog attacked.

MTA Chairman Joe Lhota says he is outraged by the video.

While MTA policy states non-service animals must be kept inside containers on subways, Roncallo still faces charges in the incident.