UPDATE: Violent All Nippon Airways Passenger 'Had PTSD,' Says Witness

A fight aboard an All Nippon Airways (ANA) flight from Narita, Japan to Los Angeles went viral this week after an agitated passenger began throwing punches at another man shortly before takeoff. At the time, it was believed the man was intoxicated. Now, the passenger on the receiving end of the altercation is speaking out. According to Ryan Humphreys, the aggressor may have been suffering from posttraumatic stress disorder (PTSD).

Humphreys, an ex-Marine, told TMZ by video Wednesday that man, shown in video clips wearing a red patterned shirt, was talking loudly to other passengers before standing up and becoming agitated. Humphreys said he was watching the man before the altercation occurred, but maintained that he hadn’t done anything to initiate the incident.

Read: Fight On Plane Erupts On All Nippon Airways Flight

“I didn’t say anything to the guy and he was like, ‘What are you looking at? I will kill you,’” Humphreys told TMZ. Humphreys said he asked the man if he was okay, to which the man responded by asking him if Humphreys was in Vegas. “It had something to do with Vegas, I don’t know,” Humphreys said.

Humphreys said the man then began assaulting a couple on the plane, allegedly attempting to choke a man and smothering his partner, a woman, in the process.

“He’s either active military or a veteran. When his shirt got ripped up I could [see] all his ink,” he said. “I would guess [he either had] PTSD or maybe off his meds. He didn’t strike me as being drunk.”

Arizona-based photographer Corey Hour captured the Monday incident, which he said began when "a passenger [started] a huge fight in his row" shortly before takeoff. At the time, the cause of the incident wasn’t clear.

"As of now and after speaking with the other passengers the motive for why he did this is still unknown," Hour said. "None of us have any idea why at all."

The man has since been identified as a 44-year-old American. When flight attendants attempted to remove him from the plane, "the man resisted, hit a woman passenger and after leaving the plane, proceeded to choke a male airline employee, which led to his arrest," according to Japan Today.

The man was reportedly charged with assault.