Transport police at Moscow's Domodedovo Airport detained a nude 38-year-old Moscow region resident on Saturday morning.
Eyewitnesses armed with cellphone cameras snapped the bizarre display, showing the man waiting patiently, his bag and clothing left on the floor, as he stood in line waiting to board his flight while making the Orthodox cross sign.
Footage shot later shows the man seated on the floor and surrounded by police officers as they attempted to figure out what the man wanted, after he attempted to run out onto the boarding ramp of his flight.
The man was said to have argued with police over his detention, before lying down on the boarding ramp floor. He was first taken to the local nurse's office, and was later transferred to a proper medical institution.
Police are still investigating the incident, and have yet to report on what caused the man's odd behaviour.