The North American Aerospace Defense Command (NORAD) detected four Russian military aircraft operating in the Alaska Air Defense Identification Zone (ADIZ) on Tuesday, Feb. 6.

"The Russian aircraft remained in international airspace and did not enter American or Canadian sovereign airspace," NORAD said in its statement. "This Russian activity in the Alaska ADIZ occurs regularly and is not seen as a threat."

A country's ADIZ begins where sovereign airspace ends and has been a defined stretch of international airspace requiring the ready identification of all aircraft in the interest of national security, NORAD added.

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Meanwhile, ABC News reported that the Russian Defense Ministry issued a press release about a long-range training flight by bombers to the Arctic that might offer a description of some of the Russian bombers in this incident, saying that two Tu-160 strategic missile carriers performed a flight over the neutral waters of the Arctic Ocean and the Laptev Sea, lasting over 10 hours.

"The flight was carried out in strict accordance with international rules for the use of airspace," Russian Aerospace Forces Lt. Gen. Sergei Kobylash was quoted by a Russian Defense Ministry statement. "Long-range aviation pilots regularly fly over the neutral waters of the Arctic, North Atlantic, Black and Baltic Seas, and the Pacific Ocean."

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