German Foreign Minister: Russia 'threatens us all' in Baltic Sea

"We, as neighbour, NATO and the EU, are countering hybrid threats with all our might, including further patrols," Wadephul told the Welt am Sonntag newspaper.

"In the Baltic Sea region, Russia threatens us all," he warned.

The shadow fleet refers to tankers and other cargo ships that Russia uses to avoid sanctions, particularly for oil transport. In recent months, there have been numerous alleged acts of sabotage by the shadow fleet on cables and pipelines in the Baltic Sea.

Since then, the underwater infrastructure has been more closely monitored.

EU ratchets up sanctions

Wadephul went on to say that the threat had become increasingly serious in recent months.

"Severed cables, disrupted signals and suspicious ships are causing us great concern," he said, describing the shadow fleet as an absolute security risk.

The EU will impose further sanctions directly on these ships, he added. "This also helps Ukraine, as the shadow fleet transports oil every day that Russia sells by bypassing sanctions."

On Tuesday, EU foreign ministers are due to formally adopt a 17th package of sanctions against Russia. It includes a further tightening of measures against the Russian shadow fleet for the transport of oil and oil products.

According to Latvian Foreign Minister Baiba Braze, approximately 84% of Russia's crude oil exports pass through the Baltic Sea with the shadow fleet. This corresponds to more than a third of Russia's budget revenues, she noted.

On Friday, the Council of the Baltic Sea States, which represents the democratic countries bordering the Baltic Sea, called for new shipping rules to allow for stronger joint action against Russia's shadow fleet.