The US Department of Defense has officially released three clips purporting to show UFOs hurtling through space.

The videos were previously published by the UFO research group To The Stars Academy between December 2017 and March 2018, and were previously acknowledged by the US Navy as its own footage.

The first clip was captured in November 2004 by the US Navy off the coast of San Diego. The other two are from January 2015, but the clips have been circulating in the public domain since 2007 and 2017, according to the Pentagon.

The clips appear to show fast-moving objects.

The Pentagon said it is releasing the videos to clear up any misconceptions on whether or not the footage circulating was real, and whether there was more to the videos.

"The aerial phenomena observed in the videos remain characterised as 'unidentified'," it added.

To The Stars Academy, which was founded by the former singer of pop-punk band Blink 182, Tom Delonge,  said that it obtained the videos through a Freedom of Information Act request.