Missile systems spotted on Moscow rooftops are unmentioned by the Kremlin.

The Kremlin has declined to confirm whether Russia is prepared to defend itself against potential attacks in the wake of social media posts showing missile defense systems installed on a number of Moscow rooftops.

Social media posts appeared to show a Pantsir-S1 mobile anti-aircraft system on the roof of a structure in central Moscow that is located about 2 kilometers (1.2 miles) east of the Kremlin, as well as a Pantsir on the roof of the Ministry of Defense building that is situated along the Moscow River and next to Gorky Park.

Pantsir-S1 mobile anti-aircraft systems appear to be installed in several sites throughout Moscow, according to pictures on social media.

The roof of the capital's primary ministry building was home to what appeared to be an anti-aircraft weapon on Friday, according to Agence France-Presse (AFP).

Dmitry Peskov, a spokesman for the Kremlin, deferred inquiries about whether Russia was concerned that Moscow would be a target, to the defense ministry on Friday.

"It is best to question the defence ministry about all actions that are done because they are responsible for guaranteeing the security of the country in general and the capital in particular," Peskov told reporters.

The AFP contacted the ministry for comment, but they did not react right away.

An air defense system called Pantsir-S1 is made to defend against a range of weaponry, such as aircraft and ballistic and cruise missiles.

Another Pantsir system was reportedly installed about 10 kilometers (6 miles) from President Vladimir Putin's home in Novo-Ogaryovo outside of Moscow, according to independent Russian-language media.

The interior minister of Ukraine's advisor, Anton Gerashchenko, shared a video on social media that appeared to show the anti-aircraft near Putin's home.

What's happening, one wonders? written Gerashchenko.

S-400 mobile surface-to-air missile units were reportedly spotted at an agricultural institute in the city as well as close to the expansive Losiny Ostrov forest park on Moscow's northern border, according to reports from earlier in the week.

On Twitter, security analyst Michael Horowitz suggested a few potential explanations: The Kremlin leadership may be worried about the prospect of a coup, which he acknowledged was a "wild guess," or Russia may be worried about "Ukrainian assaults against Moscow," the Russian leadership may be trying to play up the fear of Ukrainian attacks.

Moscow has claimed that Ukrainian forces are responsible for drone assaults on military facilities located well inside Russian territory.

Despite sending Ukraine military help worth billions of dollars from the US and other NATO countries, US President Joe Biden has stated that Washington will not supply any equipment that could be used in assaults inside of Russia.

However, Kremlin spokesman Peskov suggested the possibility of such weapons being sent in the future on Thursday, saying it would "push the battle to a whole new level."