At least four people have been killed, and children are among dozens wounded after Russia launched a massive wave of drone and missile strikes against Ukraine overnight, officials have said.

Three of the dead were pulled from the rubble of a partially destroyed apartment building in Kyiv, police said, where a rescue operation is under way after the capital was bombarded.

At least 44 people have been injured, including two children, the city's mayor said. Twenty-one of those are being treated in hospital, including one child.

It marks the third day in a row Ukraine has reported deaths, as Moscow ramps up its assault after a three-day ceasefire expired on Monday.

The overnight barrage saw more than 670 drones and 56 missiles launched across the country, President Volodomyr Zelensky said. This is among the largest attacks Russia has mounted since the start of its full-scale invasion in 2022.

In the capital, a search and rescue operation began early Thursday to look for people under the rubble of a nine-storey high-rise apartment block, which had been hit overnight.

Police said two men, aged 21 and 30, and a woman, who has not yet been identified, were found dead in the rubble of the building's destroyed entrance.

The fourth victim was a man who died in hospital, the city's police added. He had been at a petrol station which came under attack.

Kyiv Mayor Vitaliy Klychko, who visited the damaged building, said 18 apartments had been destroyed. He also said the attack had disrupted the city's water supply.

More than 1,500 rescuers and police officers are working in the aftermath of Russia's overnight attacks, almost 600 of them in Kyiv, Minister of Internal Affairs Ihor Klymenko said.

Dozens of people have been recovered from the damaged building and more than 10 people are thought to be missing, he said in a statement, with canine units involved in the search.

Teams say they have moved more than 20 cubic metres of debris and evacuated five damaged vehicles.

The strikes also damaged other residential buildings, a school, a veterinary clinic and other infrastructure in Kyiv, according to Zelensky.

The large-scale attack saw Russian drones fly across much of Ukraine, with the regions of Kremenchuk, Bila Tserkva, Kharkiv, Sumy, and Odesa also coming under fire, Prime Minister Svyrydenko said.

"Ukraine needs help in strengthening its air defense," she wrote on social media. "This is the only way to save our people and our cities."

Ukraine's Foreign Minister Andriy Sybiha condemned Russian President Vladimir Putin for the "barbaric attack", which he said showed Moscow was pursuing "aggression and terror" over peace.

He noted the attack had taken place during a crucial summit between US President Donald Trump and China's Xi Jinping, and urged the two leaders to exert pressure on Russia.

"I am certain that the leaders of the United States and China have enough leverage over Moscow to tell Putin to finally end the war," he said.

The latest attacks came shortly after a three-day, US-brokered ceasefire expired late on Monday.

Both Russia and Ukraine reported multiple violations during the truce - mostly along the vast frontline - but no large aerial attacks.

Russia resumed its attacks on Tuesday, killing nine people.

Six more people were killed in another major attack on Wednesday, which Ukraine's saw 892 drones launched from Russia.

On Thursday morning, Zelensky said a total of more than 1,560 Russian drones had targeted Ukrainian cities since Tuesday night.

He described Russia's huge assault as "definitely not the actions of those who believe the war is coming to an end", and urged Ukraine's allies not to remain silent.

In a separate development in Kyiv, a court has ordered 60 days' pretrial detention for Zelensky's former right-hand man, Andriy Yermak, over a corruption scandal.

The court said he could be released on bail of £2.35m ($3.2m) with an electronic tag.

Yermak has been named by Ukraine's anti-corruption agencies as a suspect in a money-laundering scheme involving £7.5m luxury construction project outside Kyiv.

His lawyer has described the allegations as "baseless".

After the hearing, Yermak denied the accusations against him and said he would appeal: "I'm staying in Ukraine. I have nothing to hide."

Yermak also stated that he did "not have that kind of money" for bail, but he would seek funds "among friends and acquaintances".