The US military received more than 500 reports about UFOs as of August 2022, of which over 170 newly reported sightings over the last two years remain “uncharacterized and unattributed”.

The Pentagon’s 2022 report on unidentified aerial phenomena (UAP), more commonly known as UFOs, was published by the Office of the Director of National Intelligence (ODNI) on Thursday.

The report was compiled by ODNI’s National Intelligence Manager for Aviation and the All-domain Anomaly Resolution Office (AARO).

It catalogued information from many American agencies, including the Federal Aviation Administration, Nasa, the National Oceanographic and Atmospheric Administration, and the Department of Energy.

The document includes about 510 reports of UAPs gathered across all the above agencies, of which 366 were newly identified since AARO’s creation last year.

Nearly half of the newly identified 366 UAPs were found to either be drones or “balloon-like entities”, or just airborne “clutter” of either birds or plastic shopping bags.

But about 171 of the reported sightings remain “uncharacterized and unattributed,” according to the report.

“In addition to the 144 UAP reports covered during the 17 years of UAP reporting included in the ODNI preliminary assessment, there have been 247 new reports and another 119 that were either since discovered or reported after the preliminary assessment’s time period. This totals 510 UAP reports as of 30 August 2022,” the report noted.

“Some of these uncharacterized UAP appear to have demonstrated unusual flight characteristics or performance capabilities, and require further analysis,” it said.

UFO sightings have increased significantly in the last two years.

The report highlighted safety risks to aviation posed by these UAPs specifically due to increasing use of drones.

UAPs “continue to represent a hazard to flight safety and pose a possible adversary collection threat”, while several reports “lack enough detailed data to enable attribution of UAP with high certainty”, according to the Pentagon.

“UAP events continue to occur in restricted or sensitive airspace, highlighting possible concerns for safety of flight or adversary collection activity,” the report added.

ODNI noted that it would continue “to assess that this may result from a collection bias due to the number of active aircraft and sensors, combined with focused attention and guidance to report anomalies”.

“The safety of our service personnel, our bases and installations, and the protection of US operations security on land, in the skies, seas, and space are paramount,” Pentagon press secretary Pat Ryder said in a statement on Thursday.

“We take reports of incursions into our designated space, land, sea, or airspaces seriously and examine each one,” he added.