Some United Airlines employees, some of them pilots, insist they saw a mysterious, saucer-shaped UFO hovering low over Chicago's O'Hare Airport last fall.

The Chicago Tribune reported that an object without lights was reported hovering over the terminal for several minutes before shooting up through the clouds. The paper said the workers are upset that their bosses and the government refuse to take them seriously. The workers reported that the saucerlike object left a hole in overcast skies after bolting through thick clouds with intense energy.

The Federal Aviation Administration acknowledged that a United supervisor had called the control tower at O'Hare, asking if anyone had spotted a spinning disc-shaped object. It said controllers didn't see anything, and a preliminary check of radar found nothing out of the ordinary. The FAA acknowledged the incident was reported, but it is not investigating. They're chalking it up to weather conditions.

United spokeswoman Megan McCarthy said company officials don't recall discussing any such incident from Nov. 7, but the paper said the incident was reported to the airline by as many as 12 of its own workers.

"To fly 7 million light years to O'Hare and then have to turn around and go home because your gate was occupied is simply unacceptable," said O'Hare controller and union official Craig Burzych.

The paper reported that the sighting happened 4:30 p.m., just before sunset.

The object was first noticed by a ramp worker for United, the National UFO Reporting Center told the Tribune

Some of the people who said they witnessed the incident were visibly shaken.

"I tend to be scientific by nature, and I don't understand why aliens would hover over a busy airport," a United mechanic who said he observed the metallic-looking object above Gate C17 told the Tribune. "But I know that what I saw and what a lot of other people saw stood out very clearly, and it definitely was not an [Earth] aircraft."

One United employee said a co-worker was "shaken" and "experienced some religious issues" over the sighting.

One manager for United told the paper that he ran outside his office after hearing a report of a UFO on an internal airline radio frequency.

"I stood outside in the gate area not knowing what to think, just trying to figure out what it was," he said. "I knew no one would make a false call like that. But if somebody was bouncing a weather balloon or something else over O'Hare, we had to stop it because it was in very close proximity to our flight operations."

The paper reported that all the witnesses to the event, who included several pilots, said they are certain that the object was not an airplane, helicopter, weather balloon or any other craft known to humans.