Ukrainian sources warn of a massive missile strike by Russia.
The monitoring resources claim that Russia is preparing a large-scale attack on Ukraine's energy infrastructure within 48 hours.
Up to 54 missiles are reportedly ready, including the Iskander-M, Zircon, Kaliber and S-400 systems.
The increased threat areas include Kyiv, Poltava, Kharkiv, Zaporozhye and Dnipropetrovsk.