China accused the United States on Monday of flying balloons over its territory, hitting back against Washington's claims that Beijing has been operating a fleet of surveillance aircraft around the world.
The downing of an alleged Chinese spy balloon off the coast of South Carolina earlier this month prompted a bipartisan congressional resolution condemning Beijing, while subsequent downings of other unidentified objects over North America in recent days have sparked widespread jitters and speculation as to their origins.
Only the first object has been officially attributed to China, with Beijing insisting it was a civilian craft that had blown off course.
On Monday, China sought to turn the tables on Washington, accusing it of having sent more than 10 balloons into its airspace since January 2022.
"It's not uncommon as well for the United States to illegally enter the airspace of other countries," foreign ministry spokesman Wang Wenbin said during a briefing.
"Since last year alone, US balloons have illegally flown above China more than 10 times without any approval from Chinese authorities."
Asked how China responded to those alleged incursions, Wang said Beijing's "handling (of these incidents) was responsible and professional".
"If you want to know more about US high-altitude balloons illegally entering China's airspace, I suggest you refer to the US side," he added.
AFP has contacted the US State Department and the Pentagon for comment on Beijing's allegations, but has yet to receive a response.
Over the weekend, Chinese state-affiliated media reported that an unidentified flying object had been spotted off the country's east coast -- and that the military was preparing to shoot it down.
Beijing on Monday declined to comment on that report, referring journalists to the defence ministry, which did not respond to requests for comment from AFP.
Watching the skies
Americans have been watching the skies as a growing number of aerial incursions are reported -- all of which Beijing denied knowledge of on Monday.
On Sunday the Pentagon said it had not yet determined the nature of the other three objects -- one shot down Friday over Alaska, one on Saturday over Canada's Yukon territory, and the most recent one on Sunday over Lake Huron.
But it said the object downed Sunday had been tracked for nearly a day and did not resemble the alleged Chinese surveillance balloon that was destroyed off the Atlantic coast on February 4 after traversing the country.
That first balloon prompted Washington to cancel a rare trip to Beijing by Secretary of State Antony Blinken.
President Joe Biden ordered an F-16 fighter to shoot down the latest object on Sunday "out of abundance of caution", a senior administration official said.
The object was described by the official as an octagonal structure with strings hanging off it.
Drifting at about 20,000 feet (6,000 metres) over Michigan, it could have posed a hazard to civil aviation, the official said.
The US Northern Command's General Glen VanHerck told reporters that after aircraft were sent up to inspect the newest object, they concluded that there was no indication of any threat, the same with the previous objects.
"What we are seeing is very, very small objects that produce a very, very low radar cross section," he said.
He declined to describe the shape or size of the objects, but said they were travelling very slowly, around the speed of the wind.
Speculation as to what the objects may be has flared in recent days.
"I will let the intel community and the counterintelligence community figure that out," VanHerck told reporters when asked if it was possible the objects are aliens or extraterrestrials.
"I haven't ruled out anything at this point."