Germany's defence minister has warned his country's satellites are being shadowed by Russian satellites.
Boris Pistorius cited concerns over two Luch/Olymp satellites near Intelsat satellites used by German armed forces and others.
He told a Berlin space conference: "Russia and China have expanded their capabilities for warfare in space rapidly over the past years.
"They can disrupt satellite operations, blind satellites, manipulate or kinetically destroy them."
He said Germany's military had already been targeted by jamming attacks.
Intelsat is a US-Luxembourg firm operating more than 50 satellites used by private companies as well as government agencies.
The two Russian satellites in question - launched in 2014 and 2023 - have long been accused of "loitering" and "eavesdropping" on others by stopping nearby.
French space start-up Aldoria said it observed one Russian satellite performing a "sudden close approach" to another one in May 2024.
The year before, US firm Slingshot Aerospace reported "unfriendly" behaviour - with one of the satellites showing a pattern in which it was stopping near non-Russian satellites.
Geostationary satellites rarely move and usually spend years in the same position.
The warning comes amid speculation that Russia might be behind drones that have disrupted several airports in Denmark this week.
It also follows NATO jets being scrambled last week when Russian jets violated Estonian airspace.
Military analyst Sean Bell said the closest stop observed by one of the Russian satellites was about 10km (six miles) - very close in space terms, especially as they are moving at around 3km a second.
"Every now again it moves closer to one, then closer to another - almost testing, finding out how close it can get," he told Sky News.
"It does sound a bit like Moonraker and it's definitely a threat to our military comms, and potentially space-based capabilities," he added.
Bell said operating near another satellite can give a hostile nation the chance to jam communications or manipulate it.
"Most nations realise they've not spent enough on space," he told Sky News. "So by highlighting this it secures more funding to try to do more about it."
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The German defence minister used Thursday's conference to unveil a €35bn (£30bn) investment in the country's space programmes over the next five years.
Mr Pistorius said it was important to hold talks on developing offensive capabilities in space as a deterrent to hostile actions.
As he was speaking, he told delegates: "Thirty-nine Chinese and Russian reconnaissance satellites are flying over us... so be careful what you say".
(c) Sky News 2025: Russian satellites shadowing our own, warns German defence minister