U.S. military brings down flying object over Lake Huron near Canadian border

WASHINGTON, Feb 12 (Reuters) - U.S. military fighter jets on Sunday shot down an octagonal object over Lake Huron, the Pentagon said, the fourth such incident since a suspected Chinese surveillance balloon put North American security forces on high alert.

On President Joe Biden's order, a U.S. F-16 fighter shot down the object at 2:42 p.m. local time over Lake Huron on the U.S.-Canada border, the Pentagon said in an official statement.

Though it did not pose a military threat, the object could have potentially interfered with domestic air traffic as it was traveling at 20,000 feet (6,100 m), and it might have had surveillance activities, the Pentagon said.

The object appeared to be octagonal in structure, with strings hanging off but no discernable payload, said a U.S. official speaking on condition of anonymity.

The object was recently detected over Montana near sensitive military sites, prompting the closure of U.S. airspace, the Pentagon said.

This marks the fourth unidentified flying object that has been destroyed over North America this month. U.S. officials identified the first object as a Chinese surveillance balloon, and the detection has strained U.S. relations with Beijing.

The incident raised questions about the spate of unusual objects that have appeared over North American skies in recent weeks and raised tensions with China.

"We need the facts about where they are originating from, what their purpose is, and why their frequency is increasing," said U.S. Representative Debbie Dingell, one of several Michigan lawmakers who applauded the military for downing the object.

The first object was a balloon shot down off the coast of South Carolina on Feb. 4. On Friday, a second object was shot down over sea ice near Deadhorse, Alaska. And a third object was destroyed over Canada's Yukon on Saturday with investigators still hunting for the wreckage.

"Recovery teams are on the ground, looking to find and analyze the object," Prime Minister Justin Trudeau told reporters on Sunday.

"The security of citizens is our top priority and that's why I made the decision to have that unidentified object shot down," he said, adding that it had posed a danger to civilian aircraft.

North America has been on high alert for aerial intrusions following the appearance of a white, eye-catching Chinese airship over American skies earlier this month.

That 200-foot-tall (60-meter-high) balloon - which Americans have accused Beijing of using to spy on the United States - caused an international incident, leading Secretary of State Antony Blinken to call off a planned trip to China only hours before he was set to depart.

Surveillance fears appear to have U.S. officials on high alert.

Twice in 24 hours, U.S. officials closed airspace - only to reopen it swiftly.

On Sunday, the Federal Aviation Administration briefly closed space above Lake Michigan. On Saturday, the U.S. military scrambled fighter jets in Montana to investigate a radar anomaly there.

China denies the first balloon was being used for surveillance and says it was a civilian research craft. It condemned the United States for shooting it down off the coast of South Carolina last Saturday.

U.S. Senate Majority Leader Chuck Schumer told U.S. broadcaster ABC that U.S. officials think two of the latest objects were smaller balloons than the original one.

The White House said only that the recently downed objects "did not closely resemble" the Chinese balloon, echoing Schumer's description of them as "much smaller."

"We will not definitively characterize them until we can recover the debris, which we are working on," a spokesperson said.

Canadian counterparts trying to piece together what was shot down over the Yukon may have their own challenges. The territory is a sparsely populated region in Canada's far northwest, which borders Alaska. It can be brutally cold in the winter, but temperatures are unusually mild for this time of year, which could ease the recovery effort.

Speaking to Fox News, House of Representatives Foreign Affairs Committee Chairman Michael McCaul said the balloon shot down over the South Carolina coast had been on a mission to get imagery of sensitive American nuclear sites.

"They want to get imagery, get intelligence on our military capability, particularly nuclear," McCaul said. "And they're building quite a nuclear stockpile themselves."

Republican lawmaker Mike Turner, who serves on the U.S. House Armed Services Committee, suggested the White House might be overcompensating for what he described as its previously lax monitoring of American airspace.

"They do appear somewhat trigger-happy," Turner told CNN on Sunday. "I would prefer them to be trigger-happy than to be permissive."