Video footage from the scene posted on social media shows the 29-year-old superstar picking up a metal barrier and throwing it at the vehicle.
Wild video from Felice Herrig's Instagram of Conor McGregor and company wrecking things behind the scenes. pic.twitter.com/tFqZ16JBqy— Michael Hutchinson (@TheMikeyHutch) 5 апреля 2018 г.
One passenger of the van, lightweight Michael Chiesa, was reportedly injured in the attack and taken to the hospital.
"Conor went bananas and put a beating on the van that we were in. A million security guards had to restrain him," Chiesa's coach Rick Little told MMAjunkie, adding that the fighter suffered multiple lacerations.
There is speculation that the chaotic scene stems from the announcement by UFC President Dana White that McGregor's lightweight title, which he claimed in 2016 at UFC 205, will be officially stripped this weekend, and will be claimed by either Max Holloway or Khabib Nurmagomedov, who was also in the bus.
"No interim champ. When this fight is over, one of these guys will be the champion," White said during a press conference on Wednesday, pointing to Nurmagomedov and Holloway.
Other reports say that the attack was in "retaliation" for a hotel altercation between Nurmagomedov and Artem Lobov, a teammate and good friend of McGregor's, earlier in the week.