ER star John Stamos was caught up in a mid-air altercation on Monday when a woman allegedly started threatening and striking the actor on a plane.

The unnamed woman reportedly shook the actor awake during the flight from Chicago, Illinois to Los Angeles, and then sat in, and refused to give up, his first-class seat when he went to the toilet. Stamos, who was traveling with a friend, was hit several times in the hand as the woman began shouting and threatening him.

F.B.I. agents boarded the plane when it landed, as is standard procedure when dealing with a mid-air disturbance. The officials took statements from numerous witnesses, although it appears no charges will be filed.

(This news article provided by World Entertainment News Network)