The U.S. government has received more than 700 reports of unexplained phenomena but have found no proof of extraterrestrial life, the Pentagon’s UFO office confirmed at a Thursday briefing.

The Pentagon has received hundreds of reports of new UFO sightings, including “several particularly interesting cases,” according to the director of the office that investigates these reports, but reiterated it found no evidence of alien activity.

The Pentagon office investigating reports of unidentified anomalous phenomena, the government's term for UFOs, received 21 reports last year that contain enough data for the intelligence community to continue actively investigating.

The Pentagon’s UFO office has received more than 700 reports, a newly declassified assessment reveals. It’s a dramatic increase in witness sightings and accounts that adds to a growing list and comes as former Defense Department officials claim the U.