The wave of strikes came as the EU's top diplomat was in the Ukrainian capital and with Kyiv calling on its Western allies to ramp up supplies of much-needed military aid, including air defences.

A strike on the capital Kyiv killed four people when a high-rise residential building was hit, triggering a large fire and engulfing its top floors in black smoke.

"Another massive attack against our country," Ukrainian President Volodymyr Zelensky said in a post on social media.

Missile and drone attacks were also recorded in the northeast and south of the country as well as in the western Lviv region, hundreds of kilometres from the frontlines.

At least four people were killed in the hit to the residential building in Kyiv, while one person was killed in the southern Mykolaiv region, officials said.

Ukraine's commander-in-chief Valery Zaluzhny said Russia used drones, cruise, ballistic and anti-aircraft missiles in the barrage.

He said Russia fired a total 20 drones and 44 missiles in the morning attack -- with Ukraine shooting down 15 drones and 29 missiles.

At least 35 people were injured in Kyiv, the city administration said. Another three were injured in the Kyiv region and two in the northeastern city of Kharkiv.

Russia's defence ministry said later on Wednesday it had launched an aerial attack of missiles and drones against Ukrainian "military-industrial" facilities. It said its objectives had been achieved and all targets hit.

Moscow has repeatedly denied targeting civilian areas in Ukraine, despite several documented strikes on residential buildings and the United Nations saying at least 10,000 civilians -- likely many more -- have been killed since Russia invaded in February 2022.

- 'Under the rubble' -

The strike on an 18-storey residential building in Kyiv's southern Golosiivskyi district blew out windows across several floors, and sent dark smoke cascading into the sky from the destroyed facade.

Some 60 people were evacuated, Interior Minister Igor Klymenko said.

An AFP journalist saw 13 ambulances and nine fire engines at the site on Wednesday morning, with firefighters in the building putting out the blaze.

"There are probably dead people under the rubble," Klymenko had warned earlier.

Resident Dmytro, 31, told AFP he feared his wife had been killed in the attack.

After first bringing their child down to safety after the strike, the building had filled with smoke and emergency workers stopped him from trying to go back up to collect her.

"Where there is the hole, my apartment is to the left. I was covered with shrapnel ... she had many injuries," he said.

- 'Ukraine needs help' -

As rescuers were working in Kyiv, Zelensky's top aide branded Russian President Vladimir Putin a "criminal" in a post on social media.

"Russian missiles. Kyiv. Again a residential building. This is what they spend their money on. Attacks on civilians. Ukraine needs help," Zelensky's chief of staff Andriy Yermak said.

Almost 30,000 people were also left without power in Kyiv, the energy ministry said.

Zelensky said Ukraine would "certainly respond" to the strikes.

In the southern Mykolaiv region, Mayor Oleksandr Senkevich said the attack stripped roofs off 20 houses and damaged gas and water pipes in the port city, where one person was killed.

The attack came as EU diplomacy chief Josep Borrell was making a visit to the capital.

He went to an air-raid shelter in his hotel during the attack, an AFP journalist saw.