US says UFO sightings likely secret military tests

A spike in UFO sightings in the 1960s was likely caused by tests of advanced US spy planes and space technology, a Pentagon report has concluded.

The findings, submitted in a report to Congress on Friday, also said there was "no evidence" that the US government had interactions with aliens.

Most sightings of UFOs or "unidentified anomalous phenomena" (UAP) were ordinary objects, officials said.

But they accepted the report wouldn't quell popular beliefs of alien guests.

"The proliferation of television programmes, books, movies, and the vast amount of internet and social media content centred on UAP-related topics most likely has influenced the public conversation on this topic, and reinforced these beliefs within some sections of the population," the report said.

A Pentagon spokesperson said that officials had approached the report in an open-minded way, but had simply found no evidence of extra-terrestrial visitors.

"All investigative efforts, at all levels of classification, concluded that most sightings were ordinary objects and phenomena and the result of misidentification," Maj Gen Pat Ryder told reporters.

This is a developing story. Check back here for updates.