What is a Russian spy ship doing in British waters?
Ministers have repeated warnings of security threats from Moscow after the Royal Navy was deployed to shadow a suspected Russian spy ship.
"Robust action" has been promised after a Russian spy ship was spotted "loitering" in British waters.
In what was described as "another example of growing Russian aggression", the Royal Navy nuclear-powered submarine was deployed to monitor the vessel, known as the Yantar.
The incident prompted fears for vital undersea cables which carry power and internet links into the UK.
However, ministers also admitted the foreign vessel also "complied with international rules of navigation".
Here, Yahoo News UK tries to make sense of the incident and what it means for Anglo-Russian relations.
What happened?
In a special statement to the House of Commons, defence secretary John Healy confirmed the Yantar - one of Russian President Vladimir Putin’s spy ships - had been spotted close to the UK’s "critical underwater infrastructure” in November.
To deter it, the Royal Navy ordered one of its nuclear-powered, hunter-killer submarines to surface close to the vessel.
Weeks later, the Yantar returned, prompting a change to the fleet's rules of engagement, allowing warships to sail closer to the spy vessel to monitor its activities.
At least three British ships and an RAF patrol aircraft were then deployed to "shadow Yantar’s every movement”.
It later sailed into the Mediterranean, before returning to British waters once again this week, where it was also shadowed, this time by HMS Somerset, a frigate, and patrol vessel HMS Tyne, before moving off into the North Sea.
Accusing the ship of being used for "gathering intelligence and mapping the UK’s critical underwater infrastructure", Healy used his statement in the House of Commons to send a message to Putin.
"We see you," he told the Russian leader. “We know what you are doing. And we will not shy away from robust action to protect this country.”
Why does it matter?
Despite complying with international rules of navigation, concerns remain that the presence of the vessel is another example of Vladimir Putin's antagonism towards the West at best, if not an outright attempt to sabotage key infrastructure.
Undersea cables are vital parts of Britain's energy and communications networks, carrying both the telecoms data that drives the internet and the electricity needed to power the devices connected to the web.
And it's not just off UK waters.
A Nato flotilla described as the "security camera of the Baltic" has been assembled off the coast of Estonia to deter potential sabotage at the hands of Russia.
It followed the seizure of a Russia-linked tanker by Finnish authorities after it was suspected of damaging the Finnish-Estonian Estlink 2 power line and four telecoms cables by dragging its anchor across the seabed.
There has also been damage to a cable connecting Lithuania and Sweden, and another connecting Germany and Finland.
According to Nato, more than 95 per cent of internet traffic is secured via undersea cables; they also guarantee an estimated $10 trillion worth of financial transactions every day.
"Finland has demonstrated that firm action within the law is possible. Ship captains must understand that potential threats to our infrastructure will have consequences, including possible boarding, impounding, and arrest," NATO Secretary General Mark Rutte has said.
The EU has also said that nations bordering the Baltic Sea should better prepare for infrastructure damage and intervene when the movements of "risky ships" are detected.
"The most effective way would be to intervene in advance in the traffic and movement of these ships," European Commission Vice President Henna Virkkunen said. "We need to see what new technologies can be used and how we can share this joint situation picture more effectively and more quickly so that we can combat these risks."
Healy described Russia as "dangerous but fundamentally weak", but nevertheless conceded Vladimir Putin represented "the most pressing and immediate threat to Britain".
In a May 2023 article for the RUSI defence and security think tank, Dr Sidharth Kaushal says: "In a conflict with Nato, damage to infrastructure at sea along with the targeting of infrastructure ashore would be a key part of Russia’s overall war effort, aimed at gradually eroding popular support in the West."
Dr Kaushal also says that the Yantar is equipped with sensors and appears capable of acting as a host vessel for a three-man deep-diving submersible capable of operating at depths of 20,000 feet.
Russia has denied any suggestion of wrongdoing, with a Kremlin spokesperson claiming last week that the West was trying to limit Russian oil exports "by any means necessary".
Where are the UK's waters?
UK waters covers Britain's 'inshore' and 'offshore' territories.
'Inshore' jurisdictions extend a maximum of 12 miles from the mainland, while 'offshore' areas can be up to 200 miles away and which make up the UK's exclusive economic zone (EEZ).
In the UK, large areas of its EEZ are smaller that this, however, where it meets the EEZs of nearby or neighbouring countries such as France, the Netherlands or the Republic of Ireland.
Within an EEZ, a state has control over natural resources, such as fish or offshore oil and gas.
However, vessels belonging to other nations should be allowed to travel through such waters under the right of 'innocent passage', so long as they are not suspected of attempting to take any action against the host country.
