Explosions have been reported in the Ukrainian capital, Kyiv, following two nights of heavy drone strikes.
The city’s mayor, Vitali Klitschko, urged residents to take shelter and warned about falling drone debris.
Unconfirmed reports say a plume of smoke could be seen rising from Kyiv’s Zhuliany airport.
It was Russia’s 15th air assault on the city this month. Ukrainian officials say they have destroyed most the the drones used so far.
Explosions have also been reported in the Lviv, Odesa, Vinnytsya and Khmelnytskyi regions.
In Khmelnytskyi, a strike on a military airfield damaged five aircraft and the runway, said regional authorities.
Oleksandr Scherba, the ambassador-at-large at Ukraine’s ministry of foreign affairs, told the BBC that the last few days had been very difficult for Kyiv residents.
“Almost every night, the skies look and sound like another Star Wars episode, but we don’t feel much of Russian rockets hitting their targets here within the city area. And this is all thanks to the decent countries, decent people of the world who gave us this air defence,” he said.
Living in the capital was anything but normal at the moment, Mr Scherba said, adding that the drone attacks and sleepless nights had become “part of our routine”.
On Sunday, Ukraine’s President Volodymyr Zelensky praised his country’s air defence forces after Kyiv sustained the largest drone attack since the war began.
“You are heroes,” said Mr Zelensky, after military commanders said most of the so-called kamikaze drones launched by Russia were brought down.
Russia has stepped up its attacks on Kyiv in recent weeks, seeking to overwhelm the capital’s defences.
Saturday’s overnight attack came as the people of the capital prepared to celebrate Kyiv Day, the anniversary of the city’s foundation.
In a remarkable demonstration of resilience, people took to parks, bars and restaurants in the capital to celebrate the holiday.
In its recent attacks, Russia – which launched its full-scale invasion in February 2022 – has been using kamikaze drones as well as a range of cruise and ballistic missiles.
Analysts say Moscow is seeking to deplete and damage Ukraine’s air defences ahead of its long-expected counter-offensive.
On Saturday, one of Ukraine’s most senior security officials told the BBC the country was ready to launch such an operation.
Oleksiy Danilov, secretary of the powerful National Security and Defence Council of Ukraine, said an assault to retake territory from President Vladimir Putin’s occupying forces could begin “tomorrow, the day after tomorrow or in a week”.
Ukraine has been planning a counter-offensive for months. But it has wanted as much time as possible to train troops and to receive military equipment from Western allies.