A Royal Navy warship shadowed a Russian submarine as it passed through the English Channel.
HMS Somerset located the diesel-electric submarine Krasnodar off the east coast of the UK on Friday morning.
The Plymouth-based Type 23 frigate then followed the Kilo-class submarine through the Dover Strait and the English Channel during the weekend.
Commander Tim Berry, the commanding officer of HMS Somerset, said: ‘Policing the sea both in home waters and further afield is core business for the Royal Navy.
‘Escorting foreign warships, in this case a Russian submarine, through UK waters is just part of our ongoing effort to protect our island nation.’
Last month, Somerset’s sister ship HMS Sutherland escorted two Russian warships as they sailed close to UK territorial waters.