Ukraine's capital Kyiv and Kherson in the southern part of the country continue to be targeted for attacks, apparently by Russian forces.
Explosions were reported in central Kyiv early Wednesday.
President Volodymyr Zelenskyy claimed in a video on social media that terrorists had attacked with 13 Iranian-made drones.
All the drones were reportedly shot down, but authorities say five buildings in the city were damaged by falling wreckage and debris.
Presidential office deputy head Kyrylo Tymoshenko said on Wednesday the regional government building in Kherson was damaged by Russian shelling. Ukraine forces recaptured the city last month.
No injuries were reported in the attack, but Russian forces have been shelling areas west of the Dnipro River, including Kherson, even after their withdrawal.
The Kherson region's governor revealed on social media that work to restore energy-related facilities has been hindered by repeated shelling, and that the heating system has stopped in parts of Kherson city.
The International Atomic Energy Agency stated on Tuesday that Director General Rafael Grossi and Ukrainian Prime Minister Denys Shmyhal agreed to establish a continuous presence of nuclear safety and security experts at all of Ukraine's nuclear power plants.
Grossi said the agreement is especially important at a time when Ukraine's energy infrastructure is facing unprecedented challenges in the middle of winter.
Meanwhile, Russia's presidential spokesperson Dmitry Peskov suggested that fighting would continue through the Christmas and New Year holidays.
Asked by reporters whether the Kremlin is considering a Christmas ceasefire, Peskov said, "No such offers have been received from anybody. This topic is not on the agenda."