Thick sediment coated roads in North Plainfield, New Jersey, after flash floods devastated the area.

A large number of mysterious drones have been reported flying over parts of New Jersey in recent weeks, sparking speculation and concern over who sent them and why.

A large number of mysterious drones have been reported flying over parts of New Jersey in recent weeks, sparking speculation and concern over who sent them and why.

Or are they drones being released from an Iranian mothership off the Jersey Shore — as one New Jersey congressman suggested? Story continues below photo gallery The sightings occur only at night.

A large number of mysterious drones have been reported flying over parts of New Jersey and the East Coast in recent weeks, sparking speculation and concern over who sent them and why.

A large number of mysterious drones have been reported flying over parts of New Jersey in recent weeks, sparking speculation and concern over who sent them and why.

An unverified video posted on social media allegedly shows a flaming field following a mysterious drone crash.

A large number of mysterious drones have been reported flying over parts of New Jersey and the East Coast in recent weeks, sparking speculation and concern over who sent them and why. New Jersey ...

The flying of drones for recreational and commercial use is legal in New Jersey, but it is subject to local and Federal Aviation Administration regulations and flight restrictions.