Nato countries have stepped up patrols to protect critical underwater infrastructure in the Baltic Sea, which is bordered by eight countries, and other waters. A Royal Navy submarine was ordered to surface last November close to a suspected Russian spy ship which was loitering over undersea infrastructure in UK waters.

After a series of suspected undersea cable cuttings, NATO has launched a new surveillance and deterrence mission to protect critical infrastructure under the Baltic Sea.

Cables deep under the Baltic Sea keep getting damaged - here is what Nato is doing to protect them - Nato is deploying eyes in the sky and on the Baltic Sea to protect cables and pipelines