The flurry of action comes as Moscow has massed more than 100,000 troops and heavy weaponry near Ukraine’s border and made veiled threats to invade. In response, the mayor of Kyiv last month issued a decree to inspect, catalogue and fix all Cold War-era bunkers and any underground premises that could serve as emergency shelters in case of a Russian invasion or attack.

Kyiv now runs 500 fully equipped, bomb shelters along plus over 4,000 underground safety facilities, ranging from basements to parking lots that can protect people in the event of an air raid or any attack on the capital. There is enough room for more than 2.8 million people, roughly the estimated population of Kyiv, according to the City Hall.

Russia’s state TV has dubbed such preparations “hysterics”, but they come amid the worst tensions between Russia and the West since the end of the Cold War, with Ukraine in the middle as a key battleground.

Diplomats from Moscow earlier this week held three rounds of talks with officials from the US, Nato and the Organisation for Security and Cooperation in Europe aimed at de-escalating the situation. But they ended, according to Russia’s lead negotiator, in “sort of a dead-end.”