CHICAGO (CBS)–A passenger in a Japan Airlines flight Wednesday morning tried to access the cockpit, Chicago police confirmed.

Flight #10 arrived in O’Hare’s Terminal 5 around 7:05 a.m., police said.

It was unclear whether the flight was bound for Chicago or if the aircraft was diverted to O’Hare.

The 26-year-old passenger tried to get into the cockpit while the plane was still in the air, according to police.

He was restrained by flight crew and passengers, who used what police called “mechanical devices” to control him until the plane landed.

The passenger, who police said may have a military background, was taken to Presence Resurrection Medical Center for treatment, police said.

This story is developing..