(CNN) The Russian military jammed GPS signals during a major NATO military exercise in Norway that involved thousands of US and NATO troops, the alliance said Wednesday, citing the Norwegian government.
The NATO exercise, Trident Juncture, concluded Sunday and involved some 50,000 personnel. It was labeled the alliance's largest exercise since the Cold War. Non-NATO members Finland and Sweden also participated in the exercise.
A spokesperson for the Norwegian ministry of defense acknowledged the jamming to CNN, which it said took place between October 16 and November 7, and said it would defer to the Ministry of Foreign Affairs on further questions to Russian authorities.
"Norway has determined that Russia was responsible for jamming GPS signals in the Kola Peninsula during Exercise Trident Juncture. Finland has expressed concern over possible jamming in Lapland," NATO spokesperson Oana Lungescu told CNN Wednesday.
"In view of the civilian usage of GPS, jamming of this sort is dangerous, disruptive and irresponsible," she added.
A US defense official told CNN that the jamming had "little or no affect" on US military assets during the NATO exercise.
Asked about the report of Russian jamming, NATO's Secretary General Jens Stoltenberg said the alliance was aware of the reports but did not offer additional information.
"We have seen there have been similar reports from Norway, and I cannot share more precise information with you," Stoltenberg said Sunday at a news conference marking the end of Trident Juncture.
"What I can say is that we see that cyber, electronic warfare, electronic means are used more and more frequent in different operations, and therefore we take all these issues very seriously," Stoltenberg added.
"The US is keenly aware cyber-attacks and electronic warfare are being used on and off the battlefield with alarmingly greater frequency and severity. We have experienced this in many areas where we operate, and we have observed the potentially devastating impact such measure could pose to civilian aviation," Pentagon spokesman Eric Pahon told CNN in a statement.
"We are directly addressing these expanding threats, increasing our ability to deal with these challenges and developing new ways to defend against them," he added.
The Kola Peninsula is close to the Norwegian-Russian border and is where the Russian Navy bases its northern fleet.
Although Norway is a founding member of NATO, Moscow has voiced strong opposition to the presence of NATO and US troops in the country.