Four Russian military planes flew into Alaska’s air defense zone Sunday and again Monday morning, according to North American Aerospace Defense Command (NORAD), which said the planes were deemed not a threat.
NORAD said in a press release that it “detected and tracked” the four warplanes, which were operating in the Alaska Air Defense Identification Zone (ADIZ) surrounding the U.S. and Canada but remained in international airspace.
“This Russian activity in the Alaska ADIZ occurs regularly and is not seen as a threat,” NORAD officials wrote in a statement.
While the ADIZ lies within a stretch of international airspace, NORAD tracks and detects foreign activity in the zone.
The U.S. is on edge after Russian and Chinese warships earlier this month patrolled near Alaska’s Aleutian Islands.
Moscow and Beijing have said the patrols were part of a larger set of maritime drills across international waters.
American aircraft have also had several run-ins with Russian planes operating within or near the ADIZ for years.