Russia launched a massive attack on several Ukrainian cities overnight on Monday, President Volodymyr Zelensky has said, a day after he warned of strikes over the Christmas period.
At least three people were killed, according to Ukrainian officials, including a four-year-old child, while energy infrastructure was also targeted, leaving several regions without power.
Russia launched more than 600 drones and 30 missiles, according to Ukraine.
Zelensky said people simply want to be with their families, at home, and safe in the run-up to Christmas, and said the strikes sent an extremely clear signal about Russia's priorities despite ongoing peace talks.
He added: Putin still cannot accept that he must stop killing. And that means that the world is not putting enough pressure on Russia.
Confirming a child's death in the central Zhytomyr region, local official Vitaly Bunechko said: She was taken to hospital, doctors fought for her life but could not save her in the end. Five others were injured in the strike, he added.
Meanwhile, a 76-year-old woman was killed and three people injured when a house in the Kyiv region was struck, according to Ukraine's state emergencies service.
An attack in Khmelnytskyy, western Ukraine, killed a 72-year-old, regional administration head Serhiy Tyurin said.
Polish fighter jets were scrambled in response to missiles and drones targeting west Ukraine.
The Russian defence ministry said it had targeted energy facilities and other transport infrastructure, according to Russian state news agency Tass.
Meanwhile, Ukraine reportedly struck a petrochemical plant in Stravropol, southern Russia.
With temperatures expected to fall to as low as -7C on Wednesday, Ukraine's energy operator warned of emergency power shutdowns in all regions and urged people to use energy sparingly.
Acting energy minister Artem Nekrasov said it was the ninth large attack on Ukraine's energy system this year, and that supply in the Rivne, Ternopil and Khmelnytsky regions has been almost completely lost.
The Tuesday morning attack punctured a period of relative calm in the capital Kyiv, where it has been weeks since Shahed drones have been spotted flying low overhead.
