Two British diplomats have been caught illegally filming military aircraft near an airfield in North Ossetia, Russian state TV has claimed.
Rossiya 1 said defence attache Carl Scott and assistant naval attache Ryan Coatalen-Hodgson from the Moscow embassy were spying near Mozdok base.
The Foreign Office confirmed that two British men were stopped.
Russian TV claimed an American man was also detained while taking photos at a military airfield in the Moscow region.
A UK Foreign Office spokeswoman said: "It is routine for defence attaches to travel around their host countries in the course of their diplomatic duties. This is no different in Russia.
"The defence attaches from the British Embassy in Moscow submitted to all relevant checks requested by the Russian authorities."
'Car escape'
The report on the Russian state TV channel on Tuesday evening said three "spies conducting surveillance of air bases in North Ossetia and Moscow Region have been detained".
It claimed that one "British general tried to escape in a car with diplomatic number plates" and suggested that the diplomats could be expelled.
The report showed the British men's car and their diplomatic cards.
Reporter Andrey Grigoryev said the men had no permission to be in the area, or to film.
He said Mr Scott had previously been detained by police four years ago in another region of the North Caucasus.
He added that documents had been sent to the Russian foreign ministry for an official representation to be made to the British Embassy.
The incident happened at the beginning of March, according to another TV station, state-controlled Channel One.
The Foreign Office spokeswoman said the men had passed through several checkpoints on their journey but had not been prevented from travelling.
'Spying kit' claim
Mr Grigoryev's report said the American man detained earlier this month near Chkalovskiy military airfield in the Moscow region was a plane-spotter but was in "possession of a full spying kit", including a radio scanner.
The report claimed he had been photographing aircraft of the Rossiya air group used by state officials and Russian intelligence services.
It is not clear whether the American remains in custody or has been released.
