The defence secretary has called on the public to report suspicious activity near military sites after a Russian TV crew prompted an alert at an Army base.
Gavin Williamson issued the warning after Timur Siraziev, of Channel One, was seen outside 77 Brigade's Berkshire base, the Mail on Sunday reported.
The unit works in social media and psychological operations.
An Army source said: "Timur Siraziev's suspicious behaviour was monitored by the base's security systems."
According to the Mail on Sunday, Mr Siraziev was seen with a cameraman repeatedly passing the barracks in Hermitage, Berkshire on the afternoon of 21 November.