Police probe mysterious cases of people entering New York sewer system manholes

A person descends into a sewer on a street in New York (AKI Auto Care via AP)

A series of bizarre sightings of people popping in and out of New York’s vast subterranean sewer system has the city wondering what exactly is going on, with police now probing the underground mystery.

Security cameras have recorded at least three night-time instances where groups of people entered or exited sewer tunnels via maintenance holes on streets in Brooklyn and Queens.