Mysterious drones with six-foot wingspans are making rounds throughout rural parts of the state—and we don't know why.

A fleet of mysterious drones has been spotted flying nighttime search patterns over the two rural Colorado counties, Yuma and Phillips, since last week and local law enforcement has no idea who is controlling them or what they are doing.

Authorities have no leads and are completely stumped on who or what is behind the sudden, and now regular, appearances of these mystery flyers. At least 17 drones with six-foot wingspans flying about 200 to 300 feet above ground have been spotted, according to the Phillips County Sherriff’s Office.

The drones have been observed flying in a grid pattern, searching square after square of space, and regularly appearing between 7–10 p.m. Drones have been spotted hovering above towns overnight; one sat above the town of Pavoli overnight last Friday, as eight others flew above the town of Haxtun, 10 miles away. The drones have been observed by the Sherriff’s office traveling at speeds of 30 to 40 miles per hour and haven't appeared to be racing each other.

Residents have noticed the drones, and questions are beginning to be asked, mostly about what they are doing and who is operating them. Many people are concerned that an invasion of privacy is taking place by these unknown visitors. In some cases, residents have asked if they can shoot the mysterious things down. That, specifically, has been given a strict no-go by authorities. Drones are legally considered aircraft and it's a federal crime to shoot them down. It's also illegal to try and jam the signals of the drones.

Some residents have tried to chase the drones, but have, eventually, lost them or run out of gas to give chase. Residents are asked to call authorities immediately if a drone is on their property or spotted looking into their windows, allowing a deputy to respond.

The Federal Aviation Association (FAA) has reported that the drones are not theirs, nor are they controlled by the U.S. Air Force or the U.S. Army, as confirmed by the Phillips County Sherriff’s Office. Drone pilots are not required to file flight plans for unmanned drones with the FAA unless they are in restricted airspace or near an airport. There are no state laws that prohibit drones from flying, and right now, there appears to be no criminal activity from the drones. Currently, the Sherriff’s Office does not consider the drone activity to be illegal or malicious, though it is extremely interested in knowing the who and the why. They have said they do not think they are flown by hobbyists due to the size and the large number of drones being flown.

The Phillip’s Country Sherriff’s Office asks that anyone who sees a drone on their property, especially if one lands, to call them right away. If they can get one of the drones in hand, analysis can be done to see if the drone can be traced to an owner, corporation, or organization.

Have you seen any of the mystery drones in the air in your neighborhood? What are your theories as to who's behind the fleet? Sound off in the comments with your theories and share any pictures you may have gotten. We will keep you posted on any updates.