A barrage of Russian missiles targeted Kyiv, wounding at least 53 people, officials said.
It came as Ukraine’s president sought more military support in Europe after a trip to Washington secured no new pledges.
Loud explosions rocked Kyiv at 3am on Wednesday as the city’s air defences were activated for the second time this week.
Ukraine’s air force said Russia launched 10 ballistic missiles towards the capital and all were intercepted by air defences, though debris hit homes and a children’s hospital.
The attack underscored the continuing threat to Ukraine from the Kremlin’s missile arsenal in the 21-month war.
Russia has been stockpiling its air-launched cruise missiles from its heavy bomber fleet, according to a recent assessment by the UK Ministry of Defence.
That may herald another heavy winter bombardment of Ukraine’s power grid.
Moscow last year targeted energy infrastructure in a bid to deny Ukrainians heat, light and running water and break their fighting spirit.
As winter sets in and hinders troop movements, allowing little change along the frontline, long-range air bombardment plays a growing role.
Ukraine has dwindling supplies of air defence munitions and other ammunition.
That prompted Ukrainian President Volodymyr Zelensky to visit Washington on Tuesday in an effort to persuade politicians to approve US President Joe Biden’s request for 61.4 billion dollars (£49.03 billion) for Ukraine.
His trip accomplished no breakthrough.
Mr Zelensky said on Telegram on Wednesday that he and Mr Biden agreed to work on increasing the number of air defence systems in Ukraine.
“The terrorist state has just demonstrated how crucial this decision is,” Mr Zelensky said, referring to the overnight strikes.
In Oslo on Wednesday, he met Nordic leaders who feel keenly the potential threat from nearby Russia and are among Kyiv’s staunchest supporters.
Mr Zelensky may also attend a regular European Union summit on Thursday in Brussels, where the continent’s leaders are expected to discuss their backing for Ukraine.
Officials did not confirm such a trip.
“Russia is eager to exploit divisions,” the senior leaders from Denmark, Iceland, Norway, Finland and Sweden said in a joint statement in Oslo.
“We must continue to stand united against Russia’s illegal and immoral war.”
They vowed “comprehensive assistance” for Ukraine.
“Now is not the time to tire,” the Nordic leaders said, amid signs of war fatigue among Kyiv’s foreign supporters.
Danish Prime Minister Mette Frederiksen said her government will unveil a Ukraine support package of almost 1 billion euros (£860 million) this week.
Latest Defence Intelligence update on the situation in Ukraine – 13 December 2023.
Find out more about Defence Intelligence's use of language: https://t.co/TzsUcPGtVV #StandWithUkraine 🇺🇦 pic.twitter.com/NxHlg5QG0i— Ministry of Defence 🇬🇧 (@DefenceHQ) December 13, 2023
Norway announced it will give additional air defences to Ukraine, taking them from its own stocks to ensure speedy delivery.
Separately, Latvia and Ukraine announced an agreement on the production of drones, a key part of the war.
They said they will aim to “enhance Ukraine’s technological superiority” in drone use.
Debris from intercepted missiles fell in Kyiv’s eastern Dniprovskyi district, injuring dozens of people, Kyiv mayor Vitali Klitschko said on Telegram.
Twenty people, including two children, were admitted to hospital, and 33 people received medical treatment on the spot.
An apartment building, a private house and several cars caught fire, while the windows of a children’s hospital were shattered, Mr Klitschko said.
Falling rocket debris also damaged the water supply system in the district.
It was not immediately clear what type of missile was used in the attack.
In other parts of Ukraine, 10 Russian drones were shot down, most of them in the Odesa region, the Ukrainian air force said.
The Organisation for Security and Co-operation in Europe said in a report that Russian forces this year have “continued to use explosive weapons with wide area effects in their attacks on densely populated urban areas of Ukraine … both in areas close to heavy fighting and in cities far from the contact line”.
The governmental organisation added in the report published on Wednesday that Ukrainian armed forces, though on a much smaller scale, also shelled populated areas of Ukraine that are occupied by Russia, causing civilian casualties and damage to civilian infrastructure.
