The crew of a Royal Navy warship has been forced to return to shore and isolate over Christmas after “a number of suspected Covid cases” on board.
HMS Northumberland, which has specialist sensors to hunt for foreign submarines, had been on call to protect UK waters over the festive period.
But she was forced to return to Devonport Naval Base, near Plymouth, on Wednesday.
The Navy said it will still meet all of its “operational tasks” over Christmas.
A spokesman said: “Following a number of suspected Covid cases onboard HMS Northumberland, the crew are now following health guidelines and protocols to isolate.”
He added: “The Royal Navy continues to meet all operational tasks over Christmas, as it has done throughout this pandemic.”
Last month, the Type 23 frigate escorted the Russian destroyer Vice-Admiral Kulakov as she sailed off the west coast of Scotland.
Ministers and senior military officers have warned of a significant increase in Russian submarine activity in the North Atlantic over the past few years.
The Ministry of Defence said the Royal Navy monitored nine Russian vessels near UK waters over a two-week period in late November and early December.
They included a surfaced submarine, a destroyer, a corvette and a patrol ship as well as their supporting tugs and supply ships.