A passenger on a Jetstar flight had to be restrained by cabin crew after stabbing himself with a weapon made from a toothbrush.
The flight from Darwin had to turn back and land after the bloodied man was restrained by two cabin crew members.
"There was blood everywhere,” another passenger, Adam, told the Northern Territory News.
"They tied him up, restrained him, turned around... they didn't give us any information.
"The two blokes that were there did an excellent job (restraining the man). It was all kept very, very quiet."
The Australian Federal Police interviewed passengers after the incident and took the man away.
He was not arrested and faces no charges, instead being put before mental health authorities.
Jetstar spokeswoman Simone Pregellio said the flight was turned around to ensure the safety of passengers.
"It was a serious situation," she said. "Our crew are trained to prepare for all sorts of different situations."