President Joe Biden ordered another object - the fourth in total this month - to be downed on Sunday. As it was travelling at 20,000ft (6,100m), it could have interfered with commercial air traffic, the US said.
A military commander said it could be a “gaseous type of balloon” or “some type of a propulsion system”. He added he could not rule out that the objects were extra-terrestrials.
The latest object - shot down over Lake Huron in Michigan near the Canadian border - has been described by defence officials as an unmanned “octagonal structure” with strings attached to it.
It was downed by a missile fired from an F-16 fighter jet at 14:42 local time (19:42 GMT).
The incident raises further questions about the spate of high-altitude objects that have been shot down over North America this month.
A suspected Chinese spy balloon was downed off the coast of South Carolina on 4 February after hovering for days over the US. Officials said it originated in China and had been used to monitor sensitive sites.
Since that first incident, American fighter jets have shot down three further high-altitude objects in as many days.
President Biden ordered an object to be shot down over northern Alaska on Friday, and on Saturday a similar object was shot down over the Yukon in north-western Canada.
Now that the military are specifically looking for certain objects in their skies (1), it’s likely that they will find more …
(1) Officials say US radar systems - which are more equipped for fast-moving missiles than hovering balloons - may detect more objects as their search continues.
I was listening to the wireless earlier and I was somewhat surprised to learn that the US military stated that ‘extra terrestrial’ cannot be ruled out. I do not understand the ET part of their statement as that seems to me they are forcing all kinds of speculation from the masses
I’ve always suspected that an advanced alien civilisation with the technology to travel at close to light speed across interstellar distances would arrive in Earth orbit unobserved and proceed to dispatch a fleet of small, easily detectable balloons held together with tape and string into our atmosphere.
