Russian drones attacked the southern Ukrainian port city of Odessa overnight, hitting several residential buildings and causing a fire in one, the region's military governor, Oleh Kiper, wrote on Telegram on Wednesday.
There were no initial reports of casualties or injuries.
NATO Secretary General Mark Rutte visited Odessa with Ukrainian President Volodymyr Zelensky on Tuesday.
Air raid alerts were triggered in the capital Kiev and several other cities across Ukraine as large swarms of drones entered Ukrainian airspace overnight, according to air defence authorities.
Details on the specific targets of the drones were not immediately available.
Russia has increasingly used kamikaze drones in its attacks on Ukrainian cities, often carrying out strikes at night to complicate air defence efforts and catch the civilians off guard while they sleep.
Kiev has been defending itself against an all-out Russian invasion since February 2022.
