An unidentified object that violated Canadian airspace was shot down by the US military over northern Canada on Saturday, Canadian Prime Minister Justin Trudeau said.

"Canadian and US aircraft were scrambled, and a US F-22 successfully fired at the object," Trudeau said in a tweet.

The incident comes a day after US jets shot down an unknown object off the coast of Alaska on Friday afternoon. 

Shortly before Trudeau's tweet, the North American Aerospace Defense Command (NORAD) said it detected an object flying at high altitude over Canada, but gave no further details.

In a second tweet, Trudeau added that he had spoken with US President Joe Biden and that Canadian forces would recover and "analyze the wreckage of the object."

The unknown object was the third such known violation in North American airspace over the last two weeks.

What to know about unknown objects detected so far

John Kirby, the spokesman for the US National Security Council, said on Friday at a news conference that an unknown object was downed because it posed a "reasonable threat" to safety of civilian flights.

Kirby said they did not have any information on whether the object, which he described as roughly the size of a small car, was a spying device.

Friday's incident marked a second time that a US fighter aircraft brought down a flying object in less than a week.

US Secretary of Defense Lloyd Austin told reporters on February 4 that a balloon, which was shot down that day, was being used "in an attempt to surveil strategic sites in the continental United States."

Biden also broke his silence on February 4, telling reporters that he ordered the surveillance device be taken out but that the US military had to wait until it was safe for them to do so.

China's Foreign Ministry said that the suspected surveillance device was an airship used for scientific research including meteorology, a claim that has been dismissed by US officials.

Last week, the Republican-led House, in a rare display of bipartisanship, passed a resolution condemning China's use of the surveillance balloon.

rm/ar (AP, Reuters)