Three children were among the victims in a Russian drone strike that killed at least seven people in Kharkiv.
Ukraine’s second city was hit by fire from an Iranian-made Shahed drone on Friday night, which caused a fire in which 15 homes burned down.
Regional governor Oleh Syniehubov reported that civilian infrastructure in the Nemyshlyan district had been hit by the shelling.
Interior Minister Ihor Klymenko said more than 50 people had been evacuated and that emergency workers had contained the blaze by Saturday morning.
The Ukrainian air force said air defence systems destroyed 23 out of 31 drones launched by Russia overnight.
The drones primarily targeted the north-eastern Kharkiv region and the southern province of Odesa, the statement said.
Odesa regional governor Oleh Kiper said four people were injured there by the overnight drone attacks.
The attacks came in three waves, he said. The first targeted the regional capital - the port city of Odesa. All nine drones were shot down, but the debris damaged port infrastructure and injured one person.
The second and the third waves targeted port infrastructure in the Danube river area, Mr Kiper said. A total of 12 drones were shot down and three people were injured.
Romania's ministry of national defence said on Saturday that Russia carried out overnight drone attacks on Ukraine's river ports of Ismail and Reni, near the border with Romania.
The ministry said that an F-16 jet of the Turkish Air Force was deployed from a Romanian airbase at around 1.15am to carry out "reconnaissance missions" in national airspace to monitor the situation.
Text alerts were also issued to residents in two counties adjacent to the attacks.
Nato member Romania has discovered drone debris on its territory several times before, following sustained attacks on Ukraine's port infrastructure as Moscow attempted to disrupt Kyiv's ability to export grain and other produce to world markets.
