FAA cancels 'national defense airspace' over portion of Lake Michigan

The Federal Aviation Administration on Sunday declared and then quickly canceled a "national defense airspace" over portions of Lake Michigan, according to notices from the organization.

The FAA has not said why it banned air traffic from the region for several hours, Fox News reported. 

"Pilots who do not adhere to the following [procedure] may be intercepted, detained and interview[ed] by law enforcement or security personnel," the agency said in its initial notice.

The agency restricted Montana airspace on Saturday after detecting a "radar anomaly," but no object was found, according to North American Aerospace Defense Command. Rep. Matt Rosendale (R-Mont.) said Sunday that defense officials told him "they have confidence there IS an object and it WAS NOT an anomaly," he tweeted.

The airspace closure comes after the United States downed three suspected Chinese spy balloons within one week.