U.S. military fighter jets were scrambled on Tuesday to track a Russian spy plane detected flying near Alaska, the North American Aerospace Defense Command (NORAD).

It was the fourth time in less than a week that the military command has detected and tracked a Russian IL-20 COOT, a Cold War-era reconnaissance aircraft, in the Alaskan Air Defense Identification Zone (ADIZ), a stretch of international airspace that requires the ready identification of all aircraft in the interest of national security, according to NORAD.

The same type of Russian aircraft flew over the region on Aug. 20, Aug. 21 and Aug. 24, the military command said. 

In each of the four instances, NORAD responded with its own fighter jets to track the spy plane.

In July, NORAD shared images of U.S. fighter jets intercepting Russian military aircraft inside the ADIZ. 

Other detections of Russian military aircraft in the ADIZ this year happened in April and twice in February, when NORAD said an F-35 Lightning II fighter jet intercepted two Russian Tu-95 and 2 Su-35 military aircraft in the ADIZ.

In all these previous instances, NORAD said the Russian aircraft remained in international airspace.

Earlier in January, NORAD said it sent a combat air patrol unit to monitor multiple Russian military aircraft activity in the Arctic.

Fox News’ Liz Friden contributed to this report.