WASHINGTON:The US Federal Aviation Administration (FAA) said late Saturday it had reopened some airspace in Montana after it was briefly closed for undisclosed Defence Department activities.

The FAA had issued a notice temporarily barring flights in an area about 50 by 50 nautical miles around Havre, Montana, near the Canadian border and classifying the area as “national defence airspace.”

The FAA said just before 8.30pm the airspace had been reopened.

The FAA declined to say whether the directive was related to another suspected balloon or object. The FAA issued similar actions in response to a suspected Chinese spy balloon that crossed the continental US from Montana to South Carolina and was shot down earlier this month.