A Russian submarine was spotted sailing on the surface off the Brittany coast at the end of September and was escorted by the French navy, the French navy said on its Twitter feed.
It said British and Spanish warships had also been involved in monitoring the submarine's movements.
BFM TV reported that the incident took place on Sept. 29.
(Reporting by GV De Clercq; Editing by Alex Richardson and Jonathan Oatis)
