A Brooklyn woman was arrested on Tuesday morning for assaulting her fellow D train passenger in Sunset Park, spitting at her, hitting her with an umbrella and a set of keys, and using a racial slur.

It's unclear what sparked the altercation. Video that has since been viewed millions of times on Twitter and Facebook shows the woman screaming "Fuck off!" before she begins kicking a passenger standing next to her.

She then removes her sunglasses and takes an umbrella out of her bag, striking the woman repeatedly with the umbrella while she holds her keys.

"Yo, stop I'm gonna call the cops on you, OK?" one passenger yells. "Please stop!" cries another, while two other passengers attempt to stand between the women. "Let everyone get to work!"

At around the four minute mark, the woman spits and calls the passenger a "fucking c*ink," and the train erupts in anger. "You're a disgrace to all white people," the passenger responds. "You already know she voted for Trump," exclaims Juan Ayala, the person who posted the video, and apparently, who detained the woman at the 36th Street stop at around 9 a.m. so that the police could arrest her.

Anna Lushchinskaya, 40, a Gravesend resident, was charged with menacing, criminal possession of a weapon, attempted assault, and harassment, all misdemeanors, according to a criminal complaint from the Brooklyn DA's office.

The complaint notes that the victim suffered scratches on her face and hands, and that Ayala corroborates the victim's account.

Ayala hasn't yet responded to our request for comment. Phone calls to Lushchinskaya's Legal Aid attorney went straight to voicemail, and a spokesperson for the group declined to comment.

Some observers have dubbed Lushchinskaya "Subway Sally," linking her alleged attack to a series of racist incidents that have been caught on video in the past year and gained nationwide attention.

[UPDATE // 12:30 p.m.] Another video from a different angle appears to show Ayala continuing to record Lushchinskaya. "Fucking Mohamed Atta," she mutters, apparently referring to one of the 9/11 hijackers.

"What? Bitch, I'm Dominican," Ayala responds, laughing.

Lushchinskaya then appears to knock Ayala's phone from his hands, and he responds by forcing her to the floor of the train. "No, no, no, stop, stop!" a passenger yells, as the video ends.

[UPDATE // Friday, 9:56 a.m.] Another passenger says she was assaulted by Lushchinskaya on Monday morning at the 4th Avenue/9th Street Station. Read her account here.