According to adultfyi.com:

..."This looked like something out of a bad Vince McMahon script as this guy War Machine went nuts and began taking everyone on at this party," The Vizier says. "We're talking multiple assaults and battery with the cops after him."

"War Machine’s own agent, Derek Hay, looked to be the primary target with a couple of shots to the head. Mika Tan’s Ex was KO’d as well & sent to hospital."

"I never saw anything like it," continued The Vizier. "War Machine was in kill mode. His fists were lethal weapons. Anyone who tried to get between him and Derek got taken down – hard."

War Machine responds on Twitter:

Update from TerezOwens:

Update: I have in fact spoken to War Machine's Girlfriend Alanah Rae, who confirms that the former MMA star hit her across the face last night at Brook  Haven's Birthday Party..She claims he then went on to pummel almost a dozen dudes including his own porn agent Derek Hay..who still remains in the hospital recovering...more to come. -TO