The US military shot down a fourth flying object over North American airspace in a week on Sunday over Lake Huron in Michigan, confirmed the state’s governor, Gretchen Whitmer. Whitmer said on Twitter that federal officials had been “tracking an object near [Michigan’s] airspace”. “I’m glad to report it has been swiftly, safely and securely taken down,” she said. The high-altitude unidentified object was the third to be downed by US and Canadian fighter jets in as many days, starting with a vessel about the size of a small car off the coast of Alaska on Friday, followed by a similar flying object over Yukon in Canada on Saturday. On 4 February, a large balloon which has been claimed by China was shot down off the coast of South Carolina. A Democratic Congress member from Michigan, Elissa Slotkin, confirmed that the object had been taken out by pilots from the US Air Force and national guard. “We’ll be interested in exactly what this object was and its purpose,” she said on social media. Shortly before news broke that the object had been destroyed, Slotkin said that she had heard from the US department of defense that the US military was keeping “an extremely close eye” on movements in that area. Earlier in the day the Federal Aviation Administration (FAA) had restricted civilian air traffic over Lake Michigan, as there were local reports of military jets in the area, but had lifted them after a brief time. The escalation of the drama unfolding in North American skies came as US and Canadian military are continuing to search by sea and land amid hostile weather conditions in a scramble to recover portions of the three flying objects that had already been shot down in the past week. The Democratic majority leader of the US Senate, Chuck Schumer, told ABC’s This Week on Sunday that he had been briefed by the White House and that officials were now convinced that all of the first three flying objects brought down by air-to-air missiles this week were balloons. He put the finger of blame firmly on China. “The Chinese were humiliated – I think the Chinese were caught lying,” he said. “It’s a real setback for them.” Hours later a spokesperson for the White House national security council tried to tamp down some of Schumer’s rhetoric, saying it was too early to characterise the two latest flying objects shot down over Alaska and Canada. Definitive answers would have to wait for the debris to be recovered, the official said. Schumer said that US military and intelligence agencies were “focused like a laser” on gathering information on the flying objects and then analysing what steps needed to be taken to protect American interests in future. He called it “wild” that the US government had no idea about the balloon spying program until just “a few months ago”. US and Canadian personnel are now scrambling to retrieve elements of the balloons from all four crash sites, with investigators expected to be scouring Lake Huron following the shooting down of Sunday’s flying object. Intense searches are already underway in the three previous sites of downed vessels. Canadian military are attempting to reach pieces of an unidentified flying object that was taken down within Canadian airspace on Saturday by F-22 fighter planes with the North American Aerospace Defense Command, or Norad. The vessel fell over a remote, rugged area of Yukon. The object, described as cylindrical, had been flying at 40,000ft in Canadian territory and was considered a risk to civilian air traffic. Searches by US military are also continuing in difficult circumstances off the coasts of South Carolina and Alaska in the wake of the two previous interceptions. Some debris from the first balloon to be destroyed, the largest of the three objects, was shot down on 4 February about six miles off the South Carolina coast. Underwater survey and recovery teams have already retrieved pieces from the ocean floor 50ft down. The fragments are now being taken to military laboratories for analysis. US officials have told reporters that stormy seas are slowing the mission. The Chinese government has admitted that this balloon was its own but has insisted that it was used only for weather research. The Pentagon has disputed the characterization, saying that early indications suggest that the balloon was carrying powerful equipment that could intercept communications. The balloon, flying at 60,000ft, was tracked by US military for several days as it traversed the national airspace, having initially been spotted off the coast of Alaska on 28 January. The air force decided to wait until it was over the Atlantic before shooting it down out of concern for civilians on the ground, the Pentagon said. Schumer defended that decision on Sunday against mounting criticism from Republicans who have castigated the Joe Biden White House for failing to act immediately. By following the balloon across the country, the US had gained “enormous intelligence” on what the Chinese were doing, he said. Schumer predicted that the entire object would be pieced back together in coming days. “That’s a huge coup for the United States,” he told ABC’s This Week. The search linked to Saturday’s interception is being carried out in treacherous conditions off the coast of Alaska near Prudhoe Bay, a major oil drilling community. A flying object described by US officials as being roughly the size of a Volkswagen Beetle car was shot down by F-22 fighter jets using a Sidewinder air-to-air missle on Friday afternoon. Bits of the vessel have landed in frozen sea in an area of snow and ice which is very hard to navigate amid sub-zero temperatures. Retrieval teams are using helicopters and HC-130 search-and-rescue planes because naval boats are unable to reach the location. The confluence of four downed flying objects in a week has raised tension and jangled nerves on both sides of the US and Canadian border. As a sign of the jitters, late on Saturday night, the FAA closed parts of Montana’s airspace to air traffic after a “radar anomaly” was reported. Norad fighter jets were sent to scour the skies but reportedly found nothing. However, on Sunday, a Montana congressional representative, Matt Rosendale, tweeted slightly different information, saying military officials had advised him that they were confident an object was there and that it was not an anomaly. The sudden flurry of downed flying objects has also generated political stresses internationally and domestically. The US secretary of state, Antony Blinken, postponed the first visit to Beijing by a senior American diplomat since 2018 in response to the high-altitude intrusion of the Chinese balloon. US officials have told news outlets that they have tracked the balloon program to a number of locations inside China. On the Chinese end of the billowing dispute, local news outlets cited by Bloomberg News reported on Sunday that China’s government was preparing to bring down an unidentified flying object said to have been spotted over the port of Qingdao. Fishermen in the surrounding area had been told to be alert, according to the reports. At home, the US Congress has also seen rising tension between the new Republican leadership of the House and the Biden administration over the handling of the spy objects. Republicans were critical of the Pentagon’s decision to allow the Chinese balloon to fly across the heartlands of America before bringing it down, though they have been less forthright about explaining how it was that at least three suspected Chinese spying vessels entered US airspace under Donald Trump’s previous presidential administration apparently undetected.