MEXICO CITY — Mexican air force (search) pilots filmed 11 bright, rapidly moving objects in the skies that an expert said proved the existence of UFOs, but defense officials said Wednesday no conclusions had been reached about the objects' origins.

A videotape aired Monday on national television showed a series of brilliant objects flying at more than 11,480 feet over southern Campeche state (search). The tape was filmed March 5 by air force pilots using a video camera equipped with an infrared lens.

The objects appear to accelerate rapidly and change course suddenly. At least one crew member testified in a videotaped interview that the objects encircled the military jet at a distance of at least two miles.

The pilots spotted the objects while conducting a routine drug-surveillance mission. Only three of the objects showed up on the plane's radar.

Infrared equipment can only detect heat emanating from objects. It is unable to provide an image of the objects' exact forms.

Defense Secretary Gen. Ricardo Vega Garcia gave the videotape to UFO specialist Jaime Maussan (search), who has spent 10 years studying unidentified flying objects.

Maussan claimed Tuesday the videotape was evidence that flying saucers exist. The video was especially significant since it was provided by the military, he said.

"This is historic news," Maussan said. "Hundreds of videos [of UFOs] exist, but none had the backing of the armed forces of any country. ... The armed forces don't perpetuate frauds."

But Vega denied Wednesday that the military had made any conclusions about where the lights came from or whether they were UFOs.

"This is Maussan's point of view, for that reason he was given [the video] so that he could draw his own conclusions," Vega told W Radio. "But that is his version."

Vega said he decided to release the videotape to the scientific community for study after determining it did not pose a threat to national security.

Vega also insisted that the military had not released the tape to distract the nation from other issues, such as a political corruption scandal, as some news commentators suggested.

Vega said he initially believed the objects were drug trafficking planes, "but when I began to see that they had those lights ... I realized they couldn't be such aircraft."

The defense chief said he had warned those under his command to refrain from talking about "flying saucers" and UFOs when discussing the video "because that just provokes doubts and jokes."