Ukrainian warned its residents living in the capital Kyiv to expect longer power cuts, lasting more than four hours, because of Russian attacks on energy infrastructure, reports BBC.
Currently, rolling blackouts are hitting not only Kyiv but also central regions of Ukraine, including the city of Dnipro.
President Volodymyr Zelensky admitted that about four million of their people were affected but also urged that "shelling will not break us".
This month Russia launched dozens of missiles and Iranian-made drones.
Ukraine's energy infrastructure is being seriously damaged by the air attacks as Zelensky says about a third of the country’s electric power stations have been destroyed.
The Kyiv region has lost 30% of its power capacity, the private energy company DTEK says, meaning "unprecedented" power cuts will be necessary.
"Unfortunately the scale of restrictions is significant, much larger than it was before," said DTEK director Dmytro Sakharuk.
The power cuts have meant curbs on the use of street lights and electric-powered public transport, besides the discomfort in people's homes.
The EU and other international allies of Kyiv have condemned the deliberate targeting of civilian infrastructure - attacks that Ukraine sees as war crimes.
Ukraine's second city Kharkiv, heavily damaged by Russian shelling, also faces long power cuts, along with the central cities of Zhytomyr, Poltava and Chernihiv.
Bd-pratidin English/Lutful Hoque
