The mission, dubbed Baltic Sentry, follows worry over increased Russian military activity near key undersea communication cables.

From election interference to sabotaging critical infrastructure, Russia’s hybrid warfare strategy is increasingly sowing chaos across Europe. As

Nations on the Baltic Sea, along with NATO, have stepped up security after a third incident of suspected sabotage to underwater infrastructure in a month.

Increased Russian military activity in the Baltic Sea has resulted in global calls for Denmark and other nations to inspect Moscow's oil tankers.

The Baltic Sea operation in the region bordering Russia comes as European fears of sabotage mount after a string of disruptions to underwater cables.

Estonian naval ships are taking part in stepped-up patrols in the Baltic Sea by NATO countries after undersea power and communications cables have been damaged in recent months.

The Russian Foreign Ministry said on Saturday Ukraine and Britain "had no room" for cooperation in the Sea of Azov, commenting on a new 100-year partnership agreement between Kyiv and London the two countries' leaders announced on Thursday.

NATO accuses Moscow of using tankers and other vessels ... and the "strengthening of NATO's presence in the Baltic Sea and responding to the threat posed by Russia's shadow fleet."