The Pentagon has refused to rule out the possibility that a slew of unidentified objects shot out of the sky in recent days could be linked to extraterrestrials.

A US fighter jet shot down an 'unidentified object' over Lake Huron on Sunday on orders from President Joe Biden. It was the third such downing in three days, and the latest military strike in an extraordinary chain of events over U.S. airspace that Pentagon officials believe has no peacetime precedent. 

US Air Force General Glen VanHerck said intelligence services were exploring all avenues - including the notion the three most recent objects could be linked to extraterrestrials. 

'I'll let the intel community and the counterintelligence community figure that out. I haven't ruled out anything,' VanHerck said. 'At this point we continue to assess every threat or potential threat, unknown, that approaches North America with an attempt to identify it.'

The object detected Sunday was described by defense officials as an unmanned 'octagonal structure' with 'potential surveillance capabilities' and strings attached to it.

"Strings?" To read more, click here.