United States military analysts believe Russia may be preparing for a space war, following the launch of three mysterious satellites that appear to be prototype weapons.

Russia claims it has launched three communications satellites into space since May 2014, Kosmos-2491, -2499 and -2504, but analysts say the spacecraft actually resemble prototype anti-satellite weapons, reports Yahoo News.

Per standard protocol, Moscow notified the United Nations about the launch of the three Rodnik satellites last year, and while it is typical to deploy these satellites in groups of three, this time, Moscow unexpectedly listed a fourth craft.

Like most orbital spacecraft, Rodnik satellites are not able to propel themselves since they do not have engines. That being the case, observers were surprised to see the fourth mystery satellite maneuver itself into a slightly different orbit, according to The Daily Beast.

Russia then proceeded to launch two more of the mysterious mini-fridge-sized objects over the next two years.

Analysts say the unidentified craft are able to get within a few dozen feet of other satellites, allowing the craft to potentially spy on, hi-jack or destroy other satellites.

"Looking at the history of space technology, it often starts with a small and cheap satellite that's easy to launch, then the same technology gets incorporated into something larger," Anatoly Zak, a Russian-born journalist and 'space historian', told the Daily Mail. "You can probably equip them with lasers, maybe put some explosives on them. If [one] comes very close to some military satellite, it probably can do some harm."

Former head of the Russian Federal Space Agency Oleg Ostapenko previously denied any malicious intention, saying the satellites are "absolutely peaceful vehicles" and are part of an initiative "executed together with university researchers," however, Russia will not specify the crafts purpose.

Nor will the Pentagon comment on what exactly it thinks the satellites are for, but the U.S. is paying close attention, according to Air Force spokesman Captain Nicholas Mercurio.

"As we do with all space objects - for space situational awareness purposes and to promote safe and responsible space operations – we are using our global network of sensors to watch Kosmos-2491, -2499, and -2504," Mercurio said.