Conor McGregor has been released on bail of $50,000 by a New York court.
The Irish MMA star appeared in the Brooklyn court building charged with three counts of assault and one count of criminal mischief.
The Dubliner was charged by US police after an alleged attack on a UFC bus yesterday.
McGregor presented himself to police at around 2.30am Irish time last night.
McGregor's passport was not seized and he is now allowed to board his jet and return to Ireland.
A second Irish MMA fighter - Cian Cawley, with an address at Hyde Park in Dalkey – was also charged with one count of assault and one count of criminal mischief.
His bail was set at $25,000.
Irish Mixed Martial Arts fighter Cian Cowley is led out of the 78th Precinct of the New York Police Department, 06-04-2018. Image: Julio Cortez/AP/Press Association Images
At the Brooklyn courthouse, both fighters were warned that an order of protection has been put in place in favour of four MMA fighters caught up in the saga and any contact will lead to their re-arrest.
The next court date was set at June 14th 2018.
The court heard that McGregor is accused of throwing an object through the window of the bus.
One individual on the bus is alleged to have sustained cheek abrasions and scratches to his eye and nose.
McGregor is also accused of throwing a punch at "Security detail."
The court heard that a security guard is being treated at Brooklyn Methodist Hospital.
Mr Cowley meanwhile, is accused of throwing a chair at a bus window and injuring someone who was attempting to pull him away.
Conor McGregor and Cian Cowley are arraigned in Brooklyn Criminal Court, 06-04-2018. Image: Mary Altaffer/AP/Press Association Images
McGregor, who has not fought in the UFC in 18 months, was stripped of his lightweight title earlier this week.
He had already been stripped of his featherweight title.
Earlier, in an interview with US media, UFC President Dana White said last night’s incident had “nothing to do with him being stripped” of his titles.
Mr White said the incident stemmed from a “confrontation” between UFC fighter Artem Lobov – who is a close friend of McGregor’s – and Russian fighter Khabib Nurmagomedov.
— Jim Edwards (@MMA_Jim) April 6, 2018
Videos from the scene shared on social media appeared to show a group of people gathering beside a bus at the Barclays Center in Brooklyn.
Clips from a video shot inside the vehicle showed an object hitting and cracking the windshield.
Some of the crowd appeared to step in to prevent other items, such as a guard rail, being thrown at the bus.
The UFC has been forced to cancel several fights at a planned event on Saturday night in the wake of the incident.
Lightweight fighter Michael Chiesa was hospitalised with cuts to his face.
Flyweight Ray Borg suffered 'multiple corneal abrasions' and will also be unable to fight.
UFC said a planned featherweight bout between Artem Lobov and Alex Caceres was also called off "due to Lobov's involvement in the incident."
With reporting from Stephen McNeice ...