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 practice and test their equipment.”

He added: “But definitely, nobody should behave like this, especially when you’re at war with a neighbouring country.”

Estonia first member of Nato to call out Kremlin

Estonia was 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 sits nestled between Lithuania and Poland.

There are believed to be less than 10 of the advanced electronic warfare systems in operation across the country, including the one stationed in the outpost.

Images shared on social media purportedly of the device show a large satellite dish mounted on the ground.

Dish directed to disrupt GPS signals in 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 efforts to jam signals is likely to provide a kind of invisible shield over Kaliningrad because of 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 (GNSS) 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.

Causing havoc amongst civilian use of satellite navigation systems

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.

“It’s affecting the safety of navigation, degrading the safety of navigation,” Dr Withington said.

“The good news is that aircraft and ships have other means of navigation,” he added.

“It obviously is a cause of concern if those systems are not available... so they’re a very valid argument that what the Russians are doing is deeply irresponsible from a navigation point of view.”

The Russian jamming is expected to have a larger socio-economic impact on the countries closest to Kaliningrad.

Could lead to ‘meltdown in logistics’ 

Any long-term disruption to GPS signals could lead to a meltdown in logistics, with delivery drivers left stranded without navigation systems.

But it also could undermine trust in Nato and the West by those most affected by the jammers.

General Harem said: “Whatever they [Russia] do here, one aim is to degrade our stability, self-confidence, our trust to the West, unity and cohesion.”

The Kremlin has plans to use hybrid attacks to incite social unrest in the Baltic states, according to a potential invasion scenario drawn up by the German military.

“They use different means in hybrid areas to see how we behave, how far we are to respond, and so on,” General Harem continued.

‘They have nothing to lose’ 

“They have nothing to lose. First they exercise, then they test us and then they attempt to cause some mistrust towards governments or towards Nato.”

But while his colleagues at Nato warn the alliance could be at war with Russia in the next 20 years, Estonia’s top general doesn’t believe the GPS jamming is part of Moscow’s “immediate preparations” for the conflict.