A US fighter jet shot down yet another flying object on Sunday, making it the fourth in a series of such strikes that began with the downing of a Chinese spy balloon a week ago.

President Joe Biden ordered the flying object to be downed near Lake Huron, close to the Canadian border, on Sunday afternoon.

The object could have interfered with commercial air traffic as it was traveling at 20,000ft, according to a Pentagon statement.

It was first detected above military sites in Montana on Saturday, it added.

The object, which was not deemed a military threat, has been described by defence officials as unmanned and octagonal in shape. It was downed by a missile fired from an F-16 fighter jet at 14:42 local time (19:42 GMT).

“We have no indication that it has surveillance capabilities but nor can we rule that out,” the official said on condition of anonymity.

Reflecting the heightened state of alert, US authorities briefly closed the airspace over Lake Michigan Sunday, before the latest object was shot down further towards the Canadian border.

The US aerospace command NORAD tracked the new object visually and with radar, and it was downed over the lake “to avoid impact to people on the ground while improving chances for debris recovery,” the Pentagon statement said.

Meanwhile,  Michael McCaul, chairman of the US House Foreign Affairs Committee, on Sunday accused Beijing of “an act of belligerence” regarding the first object, a Chinese balloon shot down February 4 after American officials said it was engaged in spying.

“It was done with provocation to gather intelligence data, and collect intelligence on our three major nuclear sites,” the senior Republican party leader said.

US Senate Majority Leader Chuck Schumer, who was among senior lawmakers briefed by the government, told ABC the second and third objects — one downed over Canada on Saturday, and the other shot down over Alaska on Friday — both appeared to be balloons, but “much smaller than the first large one.”