Washington( CNN) Russian military aircraft were spotted flying off the coast of Alaska for the fourth time in as many days, a spokesperson for the North American Aerospace Defense Command told CNN on Friday.

The two most recent sightings resulted late Wednesday and on Thursday, with the first involving two IL-3 8 maritime patrol aircraft and the second involving two Tu-9 5 nuclear-capable Bear bombers.

Russian aircraft never entered US airspace but US F-2 2s and Canadian CF-1 8s planes were dispatched to perform an intercept during Thursday's encounter, according to NORAD.

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