A military jet accompanied a flight to Dulles International Airport after the pilot declared an emergency minutes before landing Thursday night.
United Flight 662 was coming in from Denver around 9 p.m. when a male passenger ignored flight attendants' landing instructions and starting praying in the aisle of the plane, authorities said.
The flight landed at Dulles safely.
Crew members on the scene said the passenger may have been mentally unstable. He was taken to a hospital for an evaluation.
No one was injured.