Russia has attacked Ukraine's two largest cities Kyiv and Kharkiv early on Saturday, officials said, with one person killed and at least 15 injured.
Kyiv Mayor Vitali Klitschko said one person was killed in the capital city and four injured, including three being treated in hospital.
Klitschko said the strikes had triggered fires in districts on either side of the Dnipro River, which bisects the capital. He said heating and water supplies had been disrupted in parts of the city east of the river.
Ukraine's air force said both drones and missiles had been deployed in the assault on the capital.
Tymur Tkachenko, head of Kyiv's military administration, reported strikes in at least four districts. A medical facility was among the buildings damaged.
Kyiv has already endured two mass overnight attacks since the New Year that have knocked out power and heating to hundreds of residential buildings. Emergency workers were still engaged in restoring services to residents, with overnight temperatures dipping to minus 13 degrees Celsius (9 degrees Fahrenheit).
In Kharkiv, a frequent target 30 km from the Russian border, Mayor Ihor Terekhov said 25 drones had hit several districts over 2 and a half hours, with at least 11 people injured.
Writing on Telegram, Terekhov said the drones had struck a dormitory for displaced people, a hospital, and a maternity hospital.

US military says it's completed 13th consecutive night of strikes on Iran
Saudi-owned vessel targeted in Red Sea, crew safe, state news agency says
Rubio says US committed to helping end Ukraine war after meeting Lavrov
India's Modi promises fast-track courts on exam leaks, protesters want minister to quit
Venezuela quakes caused $19.6 billion in damage, World Bank report shows
