Iran-made "kamikaze drones" have bombarded a city near Ukraine's capital of Kyiv, leaving one person injured, according to a regional governor.
Russian forces attacked Bila Tserkva -- around 90 kilometres from Kyiv -- with six drone strikes on Tuesday night, the Ukrainian politician wrote on Telegram.
The Kyiv region had largely been removed from fighting in recent weeks as Ukraine's army stepped up its counteroffensive in the east and south.
Bila Tserkva, a city of around 200,000 people, was struck by Iranian-made Shahed-136 drones, according to regional governor Oleksiy Kuleba.
The weapons have been dubbed "kamikaze" drones as they are designed to be flown directly into enemy targets. Iran is reported to have sold hundreds of drones to Russia to support its war against Ukraine.
"At night, the enemy attacked Bila Tserkva with kamikaze drones of the Shahed-136 type. A total of 6 hits and explosions," Kuleba wrote on Telegram.
"One person was injured. The infrastructure was also damaged.
"Currently, the liquidation of the consequences of shelling is ongoing. All the necessary services, 57 rescuers and 15 units of emergency services are working on the spot, the fire is still being extinguished.
"I ask the residents not to ignore air warning signals and safety rules."
Russia has increasingly been using suicide drones in recent weeks, posing a new challenge to Ukrainian defences.
Elsewhere in Ukraine, at least five civilians have been killed and eight others have been wounded by the latest Russian shelling, according to the presidential office.
In the Donetsk region, the Russian forces shelled eight towns and villages. In Sviatohirsk, which was reclaimed by Ukrainian forces, a burial ground for civilians was found and the bodies of four civilians were discovered, according to governor Pavlo Kyrylenko.
'Fast and powerful advance' in southeastern Ukraine
In his nightly address on Tuesday, Ukraine's president Volodymyr Zelenskyy reported a "fast and powerful" advance of troops in the south of the country.
He spoke after Russia annexed four regions of Ukraine -- around 15% of its territory -- following so-called referendums that have been dismissed as shams by most of the international community.
Russian President Vladimir Putin signed laws formally absorbing Donetsk, Luhansk, Kherson, and Zaporizhzhia into Russia on Wednesday.
The United Nations has said that the annexation of Ukrainian territory by Russia will only exacerbate Moscow's human rights violations and add to the "untold suffering and devastation" inflicted on Ukrainians.
"The Ukrainian army is carrying out a pretty fast and powerful advance in the south of our country as part of the current defence operation," Zelenskyy said.
"Dozens of settlements have already been liberated from the Russian sham referendum this week alone."
Kyiv’s military said on Wednesday they have recaptured more villages in the southern Kherson region as a part of their massive counteroffensive effort.
Operational Command South said that the Ukrainian flag has been raised above Liubymivka, Khreschenivka, Zolota Balka, Biliaivka, Ukrainka, Velyka and Mala Oleksandrivka villages.
Military maps shown on Tuesday by the Russian defence ministry indicate a major retreat by forces from Dudchany, on the western bank of the Dnipro river.
Moscow's troops also appear to have left almost the entire eastern bank of the Oskil River, the last area of the Kharkiv region they still control.
A Russian-installed official in Kherson insisted on Wednesday that Ukrainian advances in the region have been halted and that it is "impossible" for Kyiv to enter the city.
Zelenskyy added in his address that he had signed a presidential decree "designating null and void all decrees of the President of the Russian Federation and all acts adopted to implement these decrees for attempted annexation of our territory from 2014 until today."
The Ukrainian president spoke after a phone call with US counterpart Joe Biden where he thanked Washington D.C. for its "continued military support".
The United States has announced a new $625 million (€629 million) security assistance package for Ukraine, which includes artillery systems with ammunition and armoured vehicles, according to the White House.
Future of the Zaporizhzhia nuclear plant
Moscow has warned that the US's decision to send more military aid to Ukraine "increases the danger of a direct military clash" between Russia and the West.
The borders of the territories Russia is claiming still remain unclear, but the Kremlin has vowed to defend Russia’s territory — including the newly absorbed regions — with any means, including nuclear weapons.
On Wednesday, the Kremlin promised to retake territories in the annexed regions, assuring that they will be "forever with Russia".
Russian media also report that the Kremlin plans to supervise operations of Europe's largest nuclear power plant in Zaporizhzhia after formally annexing the region.
Russia captured the plant in early March shortly after invading Ukraine, while Ukrainian staff continued to operate it.
Both Moscow and Kyiv have since accused each other of shelling the facility, risking a nuclear disaster. The plant's last operational reactor was shut down last month.
"The Zaporizhzhia nuclear plant is now on the territory of the Russian Federation and, accordingly, should be operated under the supervision of our relevant agencies," Deputy Foreign Minister Sergei Vershinin said on Wednesday, according to the state RIA news agency.
Meanwhile, the head of Ukraine’s nuclear power company Energoatom has claimed that he will take over managing the Zaporizhzhia nuclear plant after its director was first kidnapped and then released by Russian forces who occupy the facility.
The head of the International Atomic Energy Agency (IAEA) is reportedly set to visit Moscow in the coming days to discuss the situation at the plant.