UMAN, Ukraine Russia hurled missiles at cities across Ukraine as people slept early on Friday, killing at least 12 people in the first large-scale air strikes in nearly two months.

The early-morning attacks were carried out as Kyiv prepares to launch a counteroffensive to try to retake Russian-occupied territory.

In the central city of Uman, firefighters battled a raging blaze at a residential apartment building that had been struck on an upper floor. At least 10 people were killed, including two children, and nine were taken to hospital, regional governor Ihor Taburets said.

Rescue workers clambered through a huge pile of the smouldering rubble, carrying out a body bag away on a stretcher. A grown man wearing a face mask sobbed as he watched, and a woman came to comfort him.

"At first the windows were blown out, then came the explosion," a resident of the apartment building who gave her name only as Olga said as rescue workers dug through the debris. "Everything flew out."

In the southeastern city of Dnipro, a missile struck a house, killing a two-year-old child and a 31-year-old woman, regional governor Serhiy Lysak said. Three people were also wounded in the attack.

The Ukrainian military said it had shot down 21 out of 23 cruise missiles fired by Russia.

"This Russian terror must face a fair response from Ukraine and the world," President Volodymyr Zelenskiy wrote in a Telegram post alongside images of the wreckage. "And it will."

It was not clear what Russia was targeting in Friday's attacks though it has regularly struck civilian infrastructure, particularly energy facilities throughout the winter.

Beginning late last year Russia launched such attacks roughly weekly, though they had tapered off as winter ended, with Western countries saying Moscow had used up much of its long range missile arsenal in a failed bid to freeze Ukrainian cities.

Moscow says it does not deliberately target civilians, but its air strikes and shelling have killed thousands of people and devastated cities and towns across Ukraine. Kyiv says strikes on cities far from the front lines have no military purpose apart from intimidating and harming civilians, a war crime.

The capital Kyiv was also rocked by explosions, with officials reporting that air defence units had destroyed 11 missiles and two drones.

Two people were wounded in the town of Ukrayinka just south of Kyiv, officials said.

Explosions were also reported after midnight in the central cities of Kremenchuk and Poltava, and in Mykolaiv in the south, according to the Interfax Ukraine news agency.

The war is coming to a juncture after a months-long Russian winter offensive that gained little ground despite the bloodiest fighting so far. Kyiv is preparing a counter-offensive using hundreds of tanks and armoured vehicles sent by the West.

The main focus of fighting has for months been the eastern city of Bakhmut, as Russia tries to capture remaining parts of the industrial Donbas area that it does not yet hold.

Russia holds a swathe of territory across southern and southeastern Ukraine, and seized and annexed the Crimea peninsula in 2014.

  - Reuters