Conor McGregor has been charged with three counts of assault and one count of criminal mischief following a disturbance at the UFC 223 media day in New York.
An NYPD spokesperson said the 29-year-old Irish fighter was in custody and would be kept there until a court hearing on Friday morning.
Police had questioned McGregor, who was stripped of his UFC lightweight title on Thursday, after he gatecrashed the UFC 223 media day, sparking chaotic scenes.
Video footage emerged on social media of McGregor and his entourage storming into the Barclays Center and making their presence felt.
A video on the Instagram story of Felice Herrig, who fights at UFC 223, was captioned "Conor McGregor causing trouble" and appeared to show him attempting to throw a guard rail and chairs at a bus full of fighters.
She then said: "Tsk Tsk Conor McGregor. Are you happy now? Your little tangent injured Michael Chiesa, who is supposed to be fighting and now might not be able to fight at UFC 223."
Police said one person had been injured as the bus window was smashed, with the chaotic scenes leading to three fights being cancelled this weekend.
Michael Chiesa, who received "several facial cuts", tweeted to say the New York State Athletic Commission had decided to pull him from his bout against Anthony Pettis.
Addressing his opponent, he said: "I'm devastated to say the least. @Showtimepettis I hope to run this match up ASAP, June 9th in your backyard. That's all I have to say for now. Much love."
UFC released a statement, confirming Chiesa's injuries, and also said flyweight Ray Borg would not be taking part in his fight against Brandon Moreno due to "multiple cornea abrasions".
"Lightweight Michael Chiesa, who received several facial cuts, was deemed unfit to fight by the New York State Athletic Commission and the UFC medical team, and he was removed from his bout against Anthony Pettis," it said.
"Flyweight Ray Borg, who was scheduled to face Brandon Moreno, was deemed unfit to fight as well due to multiple cornea abrasions."
Artem Lobov, who was due to take part in a featherweight bout with Alex Caceres, was also removed from the card due to his "involvement in the incident", UFC said.
McGregor has not fought for UFC since November 2016 and was stripped of his belt this week by UFC president Dana White, after not once defending the 155-pound championship.
White also said this week he did not expect McGregor to attend Saturday's UFC 223 card. McGregor profanely responded on Twitter by saying: "You'll strip me of nothing."