At least nine people have been killed and dozens more have been injured after Russia launched a major overnight assault on cities across Ukraine.
Five people were killed in Dnipro and 25 were injured. Four people were killed in Kyiv, where at least 51 were injured following the strikes in the early hours of Tuesday, with 35 of those in hospital.
Kyiv Mayor Vitali Klitschko said two high-rise apartment buildings had been hit in the city and there are fears people are trapped under rubble.
Moscow last week warned it would launch "systematic strikes" on Ukraine in response to a drone attack last month on a dormitory in Ukraine's Russian-held Luhansk region which killed 21 people.
Kyiv Mayor Vitali Klitschko has urged people to stay in shelters. The head of Kyiv's City Military Administration, Tymur Tkachenko, said: "The enemy is striking with ballistic missiles."
Air raid warnings were in place across most of Ukraine. Large plumes of smoke could be seen rising from the centre of Kyiv.
In Russia, the Krasnodar Krai emergency response centre reported a fire at the Ilsky Oil Refinery following a drone attack. There were no casualties, according to the emergency service.
As the Russian attacks hit Kyiv through the early morning, the buzz of drones could be heard between more than a dozen loud explosions as strikes made impact.
The attack caused fires near a gas station, a construction site, and several apartment blocks, as well as two houses, Klitschko said. Blackouts have also been reported across the city.
An industrial facility has also been attacked in Zaporizhzhia.
The attacks come after Ukrainian President Volodymyr Zelensky on Monday reiterated warnings of a possible large Russian strike and urged residents to pay special attention to air raid alerts.
"Intelligence warnings regarding Russian strikes remain in effect. A massive strike is possible, they have prepared one," Zelensky said in his nightly video address.
Last week Russia said it would target military and decision-making centres in Kyiv, and urged foreigners to leave the city in what it said was a response to Ukraine deliberately striking a dormitory in Strabolinsk.
In a statement at the time, the General Staff of Ukraine's Armed Forces said it did carry out an attack near Starobilsk on the night of 21-22 May, but maintains that it struck a Russian military unit.
Kyiv said Russia's threats were "nothing short of shameless blackmail" and urged allies to increase pressure on Moscow.
Since a brief ceasefire expired in May, Russia has launched several waves of missile and drone attacks on Kyiv, among them strikes on a block of flats that killed 24 people, including three children.
A Ukrainian drone attack on the Moscow region killed three people, in what Zelensky said was an "entirely justified" response to Russian attacks.
