Hailey Bieber‘s sister, Alaia Baldwin Aronow, was arrested in Georgia earlier this week over what cops claim was a wild brawl at a bar — which involved used tampons being hurled.

The influencer was busted Saturday night in Savannah, GA after the owner of a bar called Club Elan called 911 to report an unruly patron whom he claimed was attacking his staff and refusing to leave the establishment. As it turns out … cops say that person was Alaia.

According to the police report, obtained by TMZ, when officers arrived … they met with two different bouncers and one of the bartenders there — all of whom had a similar story.

They told the cop that Alaia had gone into an employees-only bathroom, and when she was told she couldn’t be in there and had to use the public restroom — she allegedly started becoming belligerent and combative … and she’s accused of assaulting three staffers.

One security guard claims she yanked hair out of his head when he attempted to wrangle her, and another guard alleges she kicked him in the groin when he tried doing the same.

A female bartender told cops she went into the employee bathroom herself at one point — trying to show discretion for Alaia apparently — and claims she was told Alaia needed a minute to throw up and change her tampon. The staffer says she waited for a while … and when she reentered again to check on Alaia, she claims Alaia threw a tampon at her.

Eventually … the security personnel says they were able to get a hold of her and get her out of the building — and the responding officer says when he asked Alaia about all this, she claimed she was defending herself … and that the whole thing was blown out of proportion.

In the end, she was arrested on a number of charges — getting booked for simple assault, simple battery, battery and trespassing. She also posed for this mug shot at the jail.

We’ve reached out to Alaia for comment … so far, no word back.