The sickening incident took place on the New York City subway and the video has already been watched nearly a million times since being uploaded to YouTube on Monday morning.

The clip opens with Danay Howard, 21, and her friends taunting and teasing Kevin Gil, 21, for his supposed poor dress sense while they travel on an F train in Manhattan.

"You got a wack 8-ball jacket that came out in 1990," she shouts at Gil.

"Get your money game up."

Two of her friends – including 20-year-old Shanique Campbell – then see another passenger filming the incident on his phone.

They approach him and slap the phone out of his hand and onto the floor.

The rowdy group return to insulting Gil before he suddenly snaps and strikes Howard across the face, knocking her to the carriage floor.

At this point several passengers leap to her defence and attack Gil.

Howard has been charged with felony assault and disorderly conduct while her pal Campbell was charged with misdemeanour assault and disorderly conduct.

Gil and his friend Jorge Pena, 25, were also charged with misdemeanour assault and disorderly conduct.