Kyiv Mayor Vitali Klitschko warned of an "apocalypse" in the Ukrainian capital this winter if Russian air strikes on infrastructure continue, but insisted that there is no need to evacuate residents now, although they should be prepared for it.

"Kyiv could be left without light, water and heat. There could be an apocalypse, like in Hollywood movies, when it is impossible to live in houses because of low temperatures," Klitschko told Reuters. "But we're fighting and we're doing everything we can to make sure that doesn't happen," the former boxer continued.

Still, the picture is grim: there are not enough heated shelters in the capital to accommodate all 3.6 million residents in the event of full blackouts, and people must be prepared to evacuate if the situation worsens, Klitschko said. "So far we have prepared about 500 units of self-contained heat supply, but for a city of 3 million people, 500 points is nothing," he said.

Klitschko outlined one possible scenario in which the city could be left without central heating until spring, when temperatures could drop to -15 degrees Celsius.

"If there is still no power supply and the temperature remains low, we will unfortunately be forced to drain the heating system. Otherwise, the water could freeze and explode the entire water network, and the buildings will then be completely unfit for further use."

Klitschko urged residents to prepare emergency supplies of food and water, and to have clothes and documents ready to leave quickly in the event of a heating outage.

However, according to him, there is currently no need to evacuate, as the city has only a 20 percent power shortage and conditions remain stable.