A highly secret Russian electronic warfare system is interfering with the GPS guidance of airliners and ships on Nato’s eastern flank.
A surge in disruption had been detected in an area stretching all the way from Finland, through the Baltic states and Poland, Estonia’s military chief told The Telegraph.
“What we have seen is a malfunctioning of GPS for ships and air traffic,” said General Martin Harem, commander of the Estonian Defence Forces.
“And we really do not know if they [Russia] want to achieve something or just practise and test their equipment.”
He added: “But definitely, nobody should behave like this, especially when you’re at war with a neighbouring country.”
Estonia is the first member of the Nato military alliance to directly call out the Kremlin over the disruption.
Western intelligence suggests Russia has deployed a large, fixed jamming system named Tobol to its military exclave Kaliningrad, which is nestled between Lithuania and Poland.
There are believed to be fewer than 10 of the advanced electronic warfare systems in operation across the country, including the one stationed in the outpost.
Images on social media purportedly of the device show a large satellite dish mounted on the ground.
Multiple directions
Dr Thomas Withington, an expert in electronic warfare at the Royal United Services Institute think-tank, said the dish could be directed to disrupt GPS signals in multiple directions.
The effort to jam signals is likely to provide a kind of invisible shield over Kaliningrad to assuage Russia’s concerns over Nato’s arsenal of satellite-guided missiles, he added.
“This may surprise some people but I think, ostensibly, it’s actually defensive,” Dr Withington said.
“The Russian military is highly concerned by Global navigation satellite system weapons.”
While the Russian Tobol won’t stop missiles from exploding, it may cause weapons that depend on satellite signals for guidance to miss their targets, he said.
But rather than blocking munitions fired by Nato, it is causing havoc amongst civilian use of satellite navigation systems.
There have been reports of commercial airliners suddenly dropping off tracking sites, as well as warnings that ships could collide if they lose connection to the satellites.