Questions remain a day after the US government said it shot down a high-altitude object the size of a small car along the north-eastern Alaskan coast on Friday afternoon.

Though efforts by the navy, coast guard and FBI are under way to recover the object, officials had yet to identify its owner or purpose on Saturday.

Meanwhile, the North American Aerospace Defense Command (NORAD) confirmed to Canadian news outlet Global News that another “high-altitutde airborne object” has been detected over northern Canada Saturday. NORAD officials said that military aircraft are “currently operating from Alaska and Canada in support of [NORAD] activities”. American officials have not publicly commented on the airborne object seen near Canada.

The separate object that was ultimately shot down near Alaska flying at an altitude of 40,000ft, about the same level as commercial planes, and was travelling at about 20 to 40 miles per hour before it was struck down. Officials say the object had flown over parts of Alaska but was heading toward the north pole before it was struck down. American radars first identified the object’s presence around 9pm Alaska time on Thursday evening. A US warplane ultimately shot it down about 1.45pm ET on Friday.

Joe Biden briefly told reporters on Friday afternoon that the takedown of the object “was a success”, but the president did not offer any further details.

At a White House press briefing on Friday, the national security council spokesperson, John Kirby, said the US military brought the object down “out of an abundance of caution”. Once spotted, officials quickly deemed the object a threat to civilian air traffic and ordered Alaska airspace to be temporarily closed.

Fox News reported Saturday that an unnamed but senior US official confirmed to the network that the object was not detected until it had entered American airspace.

The object, shot down in territorial waters, was unmanned, officials said.

The object’s destruction in Alaska came after a tumultuous week for the Biden administration, which ordered the military to shoot down a high-altitude balloon from China over the Atlantic Ocean on 4 February.

Officials have yet to publicly give further descriptions of the object that was travelling over Alaska besides its size, altitude and speed. Still, officials have been speculating in various reports about the nature of the object.

One official told ABC News that the object was “cylindrical and silver-ish gray” and gave the “balloon-like” appearance of floating without “any sort of propulsion”. Another official from the Department of Defense told the New York Times that the object broke into pieces when it hit the frozen sea.

After the Chinese balloon was shot down, images showed what appeared to be shreds of materials as it was fished out of the ocean.

Brig Gen Pat Ryder of the Pentagon told reporters on Friday that officials “have located a significant amount of debris so far that will prove helpful to our further understanding of this balloon and its surveillance capabilities”.

From the size comparison given by officials, the object that was flying over Alaska appears to be much smaller than the Chinese spy balloon. The confirmed balloon was described as being as big as two or three buses rather than a small car like the object over Alaska.

The Alaska object was also flying at a lower altitude than the Chinese balloon, which had an altitude of 60,000ft – much higher than the level of commercial aircraft.

The Republican senator Lisa Murkowksi of Alaska told NBC News on Friday that she was concerned about the threat posed by objects over her state’s airspace.

“Quite honestly, the first line of defense is Alaska,” Murkowski said. “If it comes into Alaska airspace, if it comes into Alaska waters, we need to act.

“We need to send the message and we need to be clear and unequivocal that we don’t tolerate this.”

The appearance of the Chinese balloon over US airspace has caused a rift in the strained and delicate relationship between the Chinese and US governments. The US secretary of state, Antony Blinken, postponed an upcoming trip to Beijing, which would have been the first visit to the country by a top American diplomat since 2018.

Blinken said the spy balloon was “an irresponsible act and a clear violation of US sovereignty and international law that undermined the purpose of this trip”.

Chinese officials have apologized and maintain that the balloon was a “civilian airship” used for weather research that went off course due to limited self-steering capabilities and that its entry into US airspace was unintended.

Meanwhile, US officials say the balloon was carrying equipment that was capable of intercepting and geolocating communications.

It “was clearly for intelligence surveillance and inconsistent with the equipment onboard for weather balloons”, a senior state department official said on Thursday. “It had multiple antennas to include an array likely capable of collecting and geolocating communications.”

US officials say the balloon was part of a fleet that has been used to collect intelligence in more than 40 countries on five continents. They maintain that balloons went into US airspace at least three times during Donald Trump’s presidency and twice so far during Biden’s.

Despite the technology carried by the balloon, the Pentagon said the balloons do not give China any intelligence-collecting capacity beyond existing technology, such as satellites.