LINCOLN — A Wichita, Kansas, company that uses drones to explore for gas and oil says it isn't responsible for the mysterious drone sightings recently in southwest Nebraska.

A spokesman for Paragon Geophysical Services said Thursday that the company hasn't flown its battery-powered drone for several weeks after losing its drone pilot and because the cold weather hurts the performance of the drone.

"I'm assuming it has something to do similar to what we do," said Erick Erwin of Paragon, which uses its drone to map areas and communicate with gas and oil-related monitoring equipment in remote locations.

Drones, flying singularly or in formations of six to 12, have been spotted at night in northeast Colorado and southwest Nebraska over the past couple of weeks. Four more sightings, unconfirmed by law enforcement, were reported Wednesday night near Wallace, Nebraska, which is about 40 miles southwest of North Platte.

Lincoln County Sheriff's Corp. Derek Hannah said that a couple of deputies would be deployed again Thursday night in hopes of confirming the sightings, which began in that county on Dec. 29. So far, officials have arrived too late to confirm the reports there, he said.

"We don't know if there's just people seeing planes in the air," said Hannah.

However, law enforcement officials in Sedgwick County, Colorado, and Perkins County, Nebraska, have reported seeing the drones. 

The sightings have spawned a lot of speculation about the source and purpose of the drone flights, and have sparked investigations by local law enforcement agencies and the Federal Aviation Administration. A Facebook post on Thursday claimed that the "mystery" had been solved after spotting a Paragon truck in Grant, Nebraska, and speculating that the company was conducting the flights.

But Erwin, the company spokesman, denied that. He did speculate that it could be another company, or possibly a hunter seeking to track deer movements at night.

Hannah, the Lincoln County Sheriff's spokesman, said that agency has contacted local power companies and others, without luck, in hopes of finding out who is behind the flights.

"I'm surprised no one has shot one down yet," said Erwin. 

But deputies are still watching the skies.