US F-16 warplanes intercepted two Russian bombers in international airspace near the state of Alaska, the North American Aerospace Defense Command (NORAD) said Tuesday.

The Tu-95 bombers were intercepted the previous day after “entering and operating within the Alaskan Air Defense Identification Zone,” NORAD said in a statement.

The Air Defense Identification Zone (ADIZ) is a perimeter in which air traffic is monitored beyond the border of national airspace to provide additional reaction time in case of hostile actions.

While tensions are high between the United States and Russia over Moscow’s invasion of Ukraine, NORAD said the bombers were not seen as a threat.

“NORAD tracks and positively identifies foreign military aircraft that enter the ADIZ,” and “routinely monitors foreign aircraft movements and as necessary, escorts them from the ADIZ,” the statement said.

Russia typically holds annual nuclear exercises around this time of year, though it was unclear if the presence of the bombers was related to the drills.

Interceptions of Russian aircraft in the area — which is close to the country’s far eastern border — are relatively frequent.