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 review includes hundreds of cases of misidentified balloons, birds and satellites as well as some that defy easy explanation, such as a near-miss between a commercial airliner and a mysterious obj