Russia has uncovered a group of spy satellites, the head of its space command said in a film broadcast Sunday, which warned of "enemy" satellites that could masquerade as space junk.

"Very recently, specialists of the department of space intelligence centre uncovered a newly created group of space satellites... made for radio-technical reconnaissance of equipment on Russian territory," said the commander of Russian Space Command, Oleg Maidanovich.

Space Command is a division of the military responsible for warning of missile and air strikes and controlling Russia's defence satellites.

Maidanovich declined to say which country or countries the satellites belonged to.

The film -- called "Space Special Forces" -- was shown on defence ministry channel Zvezda as Russia marked "Space Day", commemorating the space flight of Yury Gagarin on April 12, 1961.

The 40-minute movie is "dedicated to the war for space, the battles of spy satellites," the channel's website says, echoing the language of 1980s space race between the United States and the Soviet Union.

"One talks of peaceful satellites, but there are known cases when groups of potential enemy satellites formed against our satellites, above our territory," the film's voiceover said.

"There are cases when a space satellite pretends to be space junk for years and then wakes up and starts working at the right moment."

Russia's relations with the West are at their lowest point in post-Cold War history, although cooperation has so far continued in space, notably at the International Space Station.