Britain's defence ministry said on Tuesday it was "investigating reports of an incident in the Channel," as a UK defence source told the AFP news agency that a yacht had reported a Russian warship firing warning shots.
The incident apparently took place about 20 nautical miles (37 kilometres) south of the Isle of Wight just outside British waters, according to the source.
Asked about the reported warning shots, a UK Ministry of Defence spokesperson said: "We are investigating reports of an incident in the Channel."
The defence source said it was being treated as an isolated incident not linked to the UK interception in the early hours of Sunday.
In the incident reported on Tuesday, the UK-registered yacht alleged that a Russian Navy vessel had fired the warning shots at a distance of approximately 500 yards (457 metres).
