Mysterious drone sightings have been reported in three more rural counties in the northeast corner of Colorado and at least one county in Nebraska as local law enforcement officials and residents remain clueless as to what’s flying above them at night.

The sheriffs of Lincoln, Washington and Sedgwick counties told The Denver Post on Friday that their offices have been getting calls this week about the unknown winged devices, days after initial reports out of Phillips and Yuma counties caused a national stir.

Local and national authorities say they have no idea who is operating the groups of large drones, reported to have 6-foot wingspans and spend the nighttime hours flying in grid-like patterns.

While the powers that be have no answers, the mystery aircraft have inspired a wide range of theories online. It has to be the work of a Mexican drug cartel, one commenter on The Post’s website said. No, no — it’s obviously aliens from a far-off galaxy, another replied. Perhaps it’s the History Channel looking for lost cities, or ranchers trying to track their cows, others theorized.

Thus far, however, all anyone can do is guess.

Sedgwick County Sheriff Carlton Britton said residents have been calling his office consistently since Dec. 17, reporting six to 10 drones at a time. The calls mirror those in Phillips County: The clusters of drones hover or cruise through the area between 7 and 10 p.m., flying several hundred feet in the air.

Britton said he has seen them himself — lights of an unknown color flickering from overhead.

“Oh, yeah,” the sheriff said with a chuckle, “there’s a lot of conspiracy theories floating in Sedgwick County right now.”

Britton has been batting ideas around with Phillips County Sheriff Thomas Elliott, trying to determine if any laws are being broken. As it stands right now, he said, it’s all above board — even if it’s a bit disconcerting.

“We have no idea at this point,” Britton said. “No leads and no thoughts. It’s just an odd phenomenon.”

Britton said he has spoken with a sheriff’s deputy in neighboring Deuel County, Neb., who has been chasing drones in his state the past few days. The Deuel County sheriff could not be reached Friday to comment.

Washington County Sheriff Jon Stivers has heard reports from his constituents of six drones at a time to 30.

“It’s both weird and concerning,” Stivers said. “It would be kind of nice to know what they’re doing.”

Lincoln County Sheriff Tom Nestor said he received the first report of a drone sighting in his jurisdiction Thursday night. He expects the conspiracy theorists to run wild, but Nastor said he’s most concerned with the drones colliding midair with planes from Limon’s airport or helicopters used in emergency situations.

The sheriffs said they have gotten nothing from the Federal Aviation Authority, and Elliot previously told The Post that the Air Force has denied involvement. The FAA also told The Post this week that it had no information on the mystery flyers. Neither did the Drug Enforcement Administration nor the U.S. Army Forces Command.

Local sheriff’s offices had been inundated with questions, including whether people are allowed to shoot the drones out of the sky.

“That’s not advisable,” Stivers said, indicating that it could break federal law.

The sheriffs instead recommended that residents call their offices with any more information. The Washington and Lincoln county sheriff’s offices have posted notices on Facebook asking residents to report sightings of the drones.

“I would love for someone to break it wide open,” Nestor said. “I don’t know what it is, but I would like it not to be in my county.”