From CNN just now :
Suspects
While the Sydney Morning Herald reports that a
female passenger is a suspect, Foote said that two men "of Middle Eastern origin" seemed to be the subjects of investigation and were detained by police upon arrival in Abu Dhabi.
"One of the guys had a very nervous demeanor and intermittently changed seats throughout the flight from directly in front of me to another vacant seat with his travel companion," said Foote.
"During the first flight, when he entered the bathroom about seven staff members were congregated around the area, two of whom held fire extinguishers."
Etihad flight diverted by reported bathroom arsonist - CNN.com