Authorities in the Ukrainian capital had warned that Russia was preparing the latest in a string of massive deadly strikes that have escalated the four-year-old war and dimmed the slim hopes for peace.

The Ukrainian air force said Russia had launched 73 missiles and 656 drones, adding it had downed 602 drones and 40 of the missiles.

AFP journalists in Kyiv heard air raid sirens wailing over the city before a series of loud explosions that lasted through the night sent residents with bags and blankets rushing to shelter in crowded metro stations.

Anastasia, whose residential building was damaged in the attack, said she spent a "loud" and "terrifying" night huddled in her bathroom.

- 'Nightmare' -

"All the windows were blown out completely; there are no windows at all. It wasn't just one explosion here all night. The night here was just a nightmare," she told AFP.

Ukraine's Foreign Minister Andriy Sybiga said the attack was a sign of Russian desperation, that President Vladimir Putin was bombing civilians since his forces were struggling on the battlefield.

"Putin is a war criminal and loser who has no cards except terror. Moscow is losing on the battlefield. No number of missiles can change this," Sybiga said in a social media statement.

President Volodymyr Zelensky used the attack to make a new appeal for US military support.

"Europe needs its own anti-ballistic defence so that this war can finally be brought to an end. And assistance from the United States in supplying missiles for Patriot systems is absolutely necessary," Zelensky wrote on social media.

Moscow has bombarded Ukraine almost daily since launching its invasion in February 2022, a war that is now the bloodiest on European soil since World War II, with hundreds of thousands killed and millions displaced.

Russia said that it had carried out a huge strike, including with hypersonic missiles, targeting Ukraine's military-industrial complex.

It denies that its forces target civilians.

Kyiv Mayor Vitali Klitschko said six people were killed and at least 66 were wounded in the city.

And in the industrial city of Dnipro further south, 12 people were killed including two children, when a four-storey apartment building collapsed, officials announced.

A maternity hospital with newborns and women in labour was struck in the southern port city of Odesa, authorities said, adding there were no casualties.

AFP journalists saw explosions and huge plumes of smoke billowing across Kyiv's skyline at dawn, while rescue workers cleared debris beneath residential buildings gutted in the attack.

More than 100,000 Kyiv residents temporarily lost electricity, the largest private supplier DTEK announced, while the state grid operator reported cuts in Kyiv and several other regions.

Fifteen people, including a child, were wounded in the eastern city of Kharkiv that lies near the Russian border, according to the mayor, Igor Terekhov.

- 'Protect your lives' -

The intense strikes have dulled already distant peace prospects, particularly with the White House distracted by fighting with Iran.

Ukraine also struck targets in Russia.

One person was killed in the Kursk region, near the Ukrainian border, regional governor Alexander Khinshtein said.

And a drone sparked a fire at an oil refinery in the southwestern city of Krasnodar, its headquarters said on Telegram.

Moscow's warning to foreigners, including diplomats, to leave Kyiv had sparked an outcry including at the United Nations.

Zelensky has reiterated calls to allies to allow and finance the supply of Patriot missiles, which can intercept Russian ballistic missiles.

He wrote to US President Donald Trump and the US Congress last week asking for Patriot systems to respond to the intensifying Russian air attacks.

Russia launched a record 8,150 long-range drones at Ukraine in May, an AFP analysis of Ukrainian air force data showed, up 24 percent from April.

Kyiv intercepted about 90 percent of all incoming drones and missiles in May, according to air force data -- but struggles to down ballistic missiles, some 33 of which were fired in the latest overnight barrage.

burs-jbr/jc/tw