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For more than a week now, unidentified flying drones have been unnerving residents of rural northeast Colorado ⁠— and authorities said Thursday that they're no closer to unraveling the sky-high mystery.

Law enforcement officials in Lincoln, Washington, Sedgwick, Phillips and Yuma counties said they've all been getting reports of increased nighttime activity of the small remote-control crafts in their Rocky Mountain State skies, near the state's borders with Kansas and Nebraska.

"We know that the drones have created lots of concern and have raised questions," Sedgwick County Sheriff Carlton Britton posted on his office's Facebook page Thursday.

"I would like to let the community know that we at the Sheriff's office do not have many answers at this time," the statement said. "We are working with the Federal Aviation Administration to help identify the operators of the drones."

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Britton had only this advice for his residents: Put down your guns.

"I would like to remind Sedgwick County residents that the FAA views the drones as an aircraft, which is why shooting one down is not advisable," he wrote.

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Sen. Cory Gardner, R-Colo., said he's been in contact with the FAA, which has promised to get to the bottom of the drone mystery.

"I'm encouraged that they've opened a full investigation to learn the source and purpose of the drones," Gardner said in a statement this week. "I will continue to closely monitor the situation."

Complaints even prompted a local drone operator to disavow any connection to the sightings.

UAV Recon, a Fort Collins company that works closely with power companies and law enforcement, said it "proactively" informs residents of all "of our nighttime operations."

Dusty Birge, UAV Recon's president, said it's "surprising" that drone operators "have not come forward to clarify their intent."