U.S. officials said an “unidentified object” was shot down Sunday for the third time in as many days, this time over Lake Huron in the northeastern state of Michigan, after earlier downings in Alaska and Canada.
The object has not been deemed a threat, and, like the other objects, it is still unclear to the US Defense Department what its purpose is.
Only the first balloon, shot down on February 4, was attributed by the US to China, which has denied American claims.
US President Joe Biden gave the order to shoot down Sunday's object out of an “abundance of caution,” although it was not deemed a threat by defence officials.
“What we are seeing is very small objects that produce a very, very low radar cross-section,” said US Northern Command Commander General Glen VanHerck.
The US has been more closely watching its skies after it shot down a spy balloon over Montana, with another object shot down over Alaska on Friday. American fighter jets shot down another one over Canada's Yukon Territory on Saturday.
Tensions have risen between China and the US, with US Secretary of State Antony Blinken cancelling a planned trip to Beijing after the first spy balloon was shot.