KYIV - Ukrainian officials said on Friday that Russia had launched a "massive" drone attack on its cities and infrastructure overnight, warning that Moscow could be escalating its strikes ahead of winter.
"Last night there were about 40 'Shaheds'. More than half of them were shot down," President Volodymyr Zelensky said in a post on social media.
Russia has used hundreds of Iranian-made self-detonating Shahed drones to attack targets across Ukraine since the start of the conflict.
Concerns are growing that Russia will step up missile and drone strikes in a bid to cripple Ukraine's energy infrastructure through the winter.
"We realise that with the approach of winter, Russian terrorists will try to do more damage," Zelensky added. "We will respond to the enemy. Powerfully."
Russian drones were launched at 10 regions ranging from Kharkiv and Zaporizhzhia on the front lines to Kyiv in the centre and Lviv in the west, he said.
Ukraine's air force said it had shot down 24 of the drones as well as a Russian missile.
There were no reported fatalities, though there was significant damage to residential buildings and a college in the northeastern city of Kharkiv.
Kharkiv Mayor Igor Terekhov also said a dormitory in the city housing internally displaced people had been hit.
Dozens of firefighters worked for hours to put out the blazes caused by the attacks.
Interior Minister Igor Klymenko described it as a "massive" attack, while presidential chief of staff Andriy Yermak warned Russia was "gradually increasing its air attacks on Ukraine".
In the western region of Lviv, Governor Maksym Kozytsky said Russian drone strikes had hit five critical infrastructure sites, without providing more details.
A Ukrainian military spokesperson said the drones could have been trying to identify the locations of Ukraine's air defence systems.
Russia tends to launch drones in small groups, an "obvious" feature of likely reconnaissance activity, Natalia Gumeniuk, spokesperson for Ukraine's Operational Command South told journalists Friday.
"As the winter period gets longer and the weather gets colder, the enemy may launch more massive attacks," she added.
Russia's defence ministry said overnight it had shot down two Ukrainian drones over Belgorod region, which borders Ukraine.
Separately, Ukraine said a 29-year-old man injured in an October 21 missile strike on a postal depot in the Kharkiv region had died, taking the death toll from the strike to eight.