Posts on social media on Friday indicated that air defense systems had been set up at various points in Moscow, including the headquarters of the Russian Defense Ministry.
Russian officials have not commented on reports that what appears to be a Pantsir-S1 air defense system was seen on the roof of a central Moscow building located about 2 kilometers (1.2 mi) east of the Kremlin. and the Ministry of Defense, which is located opposite Gorky Park, on the Moskva River.
A few days earlier, the presence of mobile units of S-400 surface-to-air missiles was reported near Losiny Ostrov Park on the northern border of Moscow and at an agricultural institute in the capital.
Since Russia sent troops into Ukraine about 11 months ago, it has been the target of several drone attacks or attempted attacks inside its territory. Officials said on 5 December a drone strike killed three people at a military airfield some 600 kilometers (370 miles) from the Ukrainian border.
Explosive drones also targeted the headquarters of the Russian Black Sea Fleet in Crimea, a territory annexed by Russia.
Although the United States and other NATO members have provided Ukraine with billions of dollars in military aid, US President Joe Biden has said Washington will not send weapons that could be used for attacks inside Russia.
However, Kremlin spokesman Dmitry Peskov raised the possibility of future deliveries of such weapons on Thursday, saying it would “take the conflict to a new level.”