Mexico's Defence Department is confirming that images of 11 unidentified flying objects were captured by Mexican air force pilots.

But a Canadian space observer says that while the objects are unidentified, one cannot go much further than that.

"The question is what kind of object or objects are these," Ivan Semeniuk of the Discovery Channel told CTV Newsnet.

A videotape made available to the media Tuesday showed bright objects, some like sharp points and others more like headlights, moving rapidly.

The images were taken March 5 by pilots using infrared equipment. They were conducting an otherwise normal anti-drug trafficking surveillance flight over the state of Campeche.

Reports indicate the lights surrounded the plane. Only three objects showed up on the aircraft's radar.

"... We are looking at flashing lights and they interview the pilot; he speaks about these things tracking along with him and moving at extremely high speeds," Semeniuk said.

"That is where the skepticism kicks in: No way to know how far away these things are or in fact how fast they were moving."

Semeniuk said the images aren't that different from the debris of the Mir spacecraft returning to earth.

Asked what test would have to be applied to determine whether such a UFO flight was conducted by extra-terrestrial beings, Semeniuk said there are two:

"One is that there has to be no other explanation and the second is that it has to be seen by large numbers of credible observers."

With the Mexican sighting, there is only one point of view, "so this doesn't come out any stronger than numerous other reports that we have seen like this in the past," he said.