The Royal Navy has closely watched seven Russian warships and an Algerian submarine as they passed in opposite directions through the English Channel.
British patrol ships HMS Tyne, HMS Severn and HMS Mersey were tasked with monitoring their presence.
The submarine, returning home to Africa, was tracked by HMS Severn, which "acts as the eyes and ears of the fleet in home waters", the Royal Navy said.
Her Commanding Officer, Commander Philip Harper, said: "It has been a pleasant duty to welcome our Algerian friends for their transit of UK waters in great weather as they head home."
Sailing westward, HMS Mersey stayed with a trio of Russian vessels – frigate Admiral Kasatonov, a supporting tug Nikolay Chiker and tanker Vyazma – off the French coast and stayed close until they moved into the North Sea.
High winds and large sea states meant the Russian ships spent longer than usual passing through the Channel.
HMS Mersey's company worked continuously to ensure the safe passage of the Russian vessels, according to the Navy.
Navigating officer Lieutenant Thomas Bees said that "the Russian Federation naval vessels operated in a safe and professional manner throughout their transit".
Lieutenant Commander Edward Munns, spoke of HMS Mersey's "flexibility" in being able "to react to a short notice tasking quickly and successfully".
He praised his ship's company's display of "outstanding professionalism to switch their mindset to national tasking".
Before this Russian group transited through the Channel, HMS Mersey was given assistance from HMS Tyne to constantly watch four Russian vessels sailing through the area on their way towards the Atlantic.
They included three Ropucha-class amphibious ships capable of landing tanks, Minsk, Kaliningrad and Korolev, and the frigate Boiky, the Navy said.
Located in the North Sea, they were followed through the Dover Strait and into the Channel ahead of their arrival in the open waters of the North Atlantic.
The Portsmouth-based offshore patrol ships also worked with allied NATO ships and aircraft.
HMS Tyne's operations officer, Lieutenant Justin Shirtcliff, said: "All interaction with Russian units was safe and professional throughout the operation."
Lieutenant Nicholas Ward, Tyne's executive officer, added: "We have quickly switched from conducting fishery protection to working with our NATO allies monitoring foreign warships operating close to the UK.
"We're all proud on Tyne to be part of the team protecting the nation's interests."
Cover image: Russian ships passing through the Dover Strait (Picture: Royal Navy).