Russia has launched massive missile strikes across Ukraine, including the capital Kyiv, causing power and water outages, Ukrainian officials say.
At least two blasts were reported in Kyiv. One resident told the BBC his district was now without electricity.
In the north-eastern city of Kharkiv, critical infrastructure facilities were hit, the local authorities said.
The strikes come after Russia blamed Ukraine for a drone attack on its Black Sea Fleet in the annexed Crimea.
On Monday, 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.
Ukraine's Air Force spokesman Yuriy Ihnat told Ukrainian TV that Russia had used its strategic bombers to carry out the attack.
Andriy Yerkmak, the head of President Volodymyr Zelensky's office, said that "Russian losers are continuing to fight against peaceful objects".
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".