Russia has fired a barrage of missiles at targets across Ukraine for the eighth time in eight weeks.
Residents of Odesa in the south were left without water and the whole of the Sumy region suffered a blackout.
Previous attacks have hit the country’s energy grid, leaving millions without electricity and heat as winter arrives.
Ukrainian and Western leaders have condemned the attacks on infrastructure as war crimes, because of the harm caused to civilians.
Warnings that Russia was planning a fresh wave of attacks have been circulating for several days.
They come just hours after a series of reported explosions at two airbases deep inside Russia, in which at least two TU-95 long-range strategic bombers are said to have been damaged.
Reports on Russian military blogs suggest both bases were attacked by Ukrainian drones. Ukraine has yet to comment. TU-95 bombers have been used extensively to launch cruise missiles at Ukraine.