A wave of Russian missiles have hit cities across Ukraine, officials say.
Kyiv Mayor Vitaly Klischko said there had been several blasts in the capital, causing at least one death. A hotel has also been damaged.
The attacks happened two days after Russia carried out one of the largest air strikes since the start of the war.
Ukraine President Volodymyr Zelensky had warned Russia could launch more attacks to make Ukrainians “celebrate the New Year in darkness”.
Russia has been targeting Ukraine’s energy sector in the past few months, destroying power stations and plunging millions into darkness during the country’s freezing winter.
Several senior Ukrainian officials have alluded to the strikes in social media posts, saying that Russia would not succeed in ruining their celebrations.
Mykolaiv Governor Vitaly Kim said on Facebook that Russian missile launches had been reported.
“The occupiers have decided to try to spoil the day for us,” he said.
In Kyiv, people rushed to shelters as air raid sirens sounded.
Emergency workers were sent to several districts hit by explosions.
Deputy presidential chief of staff Kyrylo Tymoshenko said on Telegram that a hotel had been damaged.
Air defence has been activated in regions across the country.
In the western city of Khmelnytskyi, a drone attack injured two people, Mr Tymoshenko added.
The attacks came as Russian President Vladimir Putin accused the West of “provoking” Moscow to launch its invasion of Ukraine on 24 February.
In a combative New Year address, Mr Putin said: “The West lied about peace. It was preparing for aggression… and now they are cynically using Ukraine and its people to weaken and split Russia.”
Ukraine and the West reject Russia’s claims about the start of the aggression.
The Ukrainian government has pleaded with Western leaders to provide it with additional air defences, and US President Joe Biden recently agreed to supply its Patriot system.
The Kremlin rejected Ukraine’s suggestion that peace talks could begin in 2023.__BBC