Mexico City - Mexico's largest television network on Monday and Tuesday broadcast footage taken by air force pilots of what they say are unidentified flying objects (UFOs).

The footage shows bright lights with "movements and characteristics that do not have - up to now - a scientific explanation," according to the Televisa network.

The air force pilots are heard expressing amazement on the tape.

A frame-by-frame analysis shows 16 UFOs, according to the network.

Televisa said the film was taken with an infrared camera and there are no alterations.

"It is one of the most important film documents we have been able to access, especially because it comes from an official source," said Jaime Mausan, a journalist who has been tracking the UFO phenomenon for more than 25 years.

The daily La Jornada on Tuesday however dismissed the brouhaha as "circus".

On January 31 two Mexican air force photographers said they videotaped what they believed were eight UFOs that overflew Mexico City and the city's international airport for several hours. - Sapa-AFP