Ukrenergo, the national energy company of Ukraine, has asked civilians to "charge everything" by Thursday morning because of expected electricity cuts as power plants were hit by Russian missiles.
In a statement on Wednesday night, the company said that there had been more attacks on power facilities in the past 10 days than in the whole preceding period since Russia waged its war on February 24, reports the BBC.
"Tomorrow (Thursday) we will apply controlled, calculated consumption restrictions, which we have to do, to ensure the system functions in a balanced way," the statement added.
Outages of up to four hours at a time will affect the whole country on Thursday, the grid operator said, adding that phones, power banks, torches and batteries must be charged.
The company also appealed to Ukrainians to stock up with water and ensure they have "warm socks and blankets and hugs for family and friends".
Ukrenergo further said that restrictions "may be applied throughout Ukraine from 7 a.m. to 10 p.m." and advised citizens to check the regional network operators' websites to see where and when exactly.
The warning comes after Russian missiles hit energy plants across the country earlier in the day which were part of a wave of series of strikes that began on October 10.
Also appealing to to the citizens, President Volodymyr Zelensky said on Wednesday night: "Please do not turn on unnecessary electrical appliances. Please limit your electricity consumption and use those appliances that consume a lot of energy.
"Tomorrow, it is very important that the consumption is as conscious as possible, and thus the schedules of stabilisation blackouts will be shorter.
"We will do everything possible to restore the normal energy capabilities of our country. But it takes time. And this requires our joint efforts."
According to the President, 30 per cent of Ukrainian power stations had been damaged by the recent Russian air strikes.