Ukraine says power and water supply across the country has been badly hit after Russia launched more than 50 missiles targeting critical facilities.
In the capital Kyiv, 80% of residents were without water, and about 350,000 apartments had no electricity, Mayor Vitaliy Klitschko said.
In the north-eastern city of Kharkiv, energy facilities were struck.
Russia said its long-range high-precision weaponry targeted Ukraine’s military command and energy systems.
The country’s defence ministry added that all «designated objects were hit».
The strikes come after Russia blamed Ukraine for a drone attack on its Black Sea Fleet in the annexed Crimea.
Mr Klitschko reported water shortages in Kyiv after an energy facility near the city had been damaged in the Russian attack. He said the supply would be partially restored within three to four hours.
He also said that engineers were urgently deployed to restore electricity supply.
The city authorities said that in Kyiv itself «no hits were recorded» due to «the effective work of the air defence forces».
On Monday morning, missile strikes were also reported in the central Vinnytsia region, as well as Dnipropetrovsk and Zaporizhzhia in the south-east, and Lviv in western Ukraine.
A facility at the Dnipro hydroelectric power plant in the Zaporizhzhia region was also reportedly hit.
Overall, 18 facilities – most of them energy-generating – were hit in 10 regions of Ukraine, Prime Minister Denys Shmyhal said, adding that «hundreds of localities in seven regions» were left without power.
It was not immediately known if there were any casualties.
Residents in the regions under attack were urged to remain in shelters, amid fears more strikes could follow. They were also warned that «emergency power outages» were being rolled out across the country.
In neighbouring Moldova, the authorities reported that a missile shot down by Ukraine fell in the «northern end of the town of Naslavcea» near the border with Ukraine. There were no reports of any casualties – but windows were smashed in several houses.
Ukraine’s Air Force spokesman Yuriy Ihnat told Ukrainian TV that Russia had used its strategic bombers to carry out its «massive» strikes.
Ukraine’s military later said that 44 out of more than 50 X-101 and X-555 cruise missiles launched from Russia’s Rostov region and also the Caspian Sea had been shot down.
Ukrainian Foreign Minister Dmytro Kuleba said that «instead of fighting on the battlefield, Russia fights civilians».
Russia has carried out several waves of deadly missile and drone attacks in recent weeks, reportedly destroying almost a third of Ukraine’s power stations and other energy-generating facilities ahead of the cold winter period.
Ukraine and its Western allies have repeatedly said that targeting civilian infrastructure amounted to war crimes.
On Saturday, one Russian warship was damaged in the port city of Sevastopol in a drone attack, the Russian defence ministry said. It also accused British specialists of having trained the Ukrainian soldiers who then carried out the strikes in Crimea – Ukraine’s southern peninsula, annexed by Russia in 2014.
Moscow provided no evidence to back its claims.
Ukraine has not commented on the issue, while the UK defence ministry said Russia was «peddling false claims on an epic scale».