Ukrainian authorities are reporting a new wave of Russian missile strikes on Thursday, with air raid sirens sounded all across the country
Russia pounded gas production facilities and a major missile factory in new strikes on critical infrastructure, officials said.
It comes as a light blank of snow covered the capital Kyiv and other parts of the country.
Explosions were heard in several parts of the country, including the southern port of Odesa, as civilians were urged to take shelter as air raid warnings were issued.
Prime Minister Denys Shmyhal said targets included a gas production facility and the huge Pivdenmash missile factory in the central city of Dnipro.
Multiple explosions were reported in the city where two infrastructure objects were damaged, according to the Ukrainian president's office.
At least 14 people were reported wounded, including a 15-year-old girl.
The president's office said four people were killed in a missile attack overnight on a residential building in the southeastern region of Zaporizhzhia. Three more were wounded in an attack on the northeastern city of Kharkiv, and three were hurt in Odesa.
Air defence systems were operating in the central Kyiv region, Governor Oleksiy Kuleba said. The Kyiv city administration said two missiles were shot down over the capital.
Snow was reported in Ukraine on Thursday morning as the country suffered major power cuts after heavy Russian strikes on energy infrastructure. Moscow has increasingly resorted to targeting Ukraine’s power grid as winter approaches as its battlefield losses mount.
Widespread strikes on Tuesday reportedly left around 10 million people without power.
Kuleba warned on Wednesday that the coming week would be "difficult", with temperatures that could go down "to minus 10 degrees Celsius".
Ukraine's national electricity operator Ukrenergo announced that power cuts would be extended throughout Thursday due to the "worsening situation".
In the east, Ukraine said it faced fierce attacks from Russian forces reinforced with troops withdrawn from Kherson in the south.
Fighting was heavy in the eastern Donetsk region, including the towns of Pavlivka, Vuhledar, Maryianka, and Bakhmut, Ukrainian presidential adviser Oleksiy Arestovych said.
Ukrainian forces had repelled attacks on the Donetsk towns of Avdiivka and Bilohorivka, according to a military analyst.
Arestovych said that redeployed Russian forces had also gone on the attack in the southern Zaporizhzhia region and may be planning to launch another offensive in Kharkiv in the north, where they were pushed back by Ukraine earlier in the conflict.
Vladimir Rogod, a Russian-installed official in the Russian-controlled part of Zaporizhzhia, said a Ukrainian missile also struck a village there, killing two other people and wounding nine.
The Moscow-backed RIA Novosti news agency stated that Ukrainian forces now control around 1% of territory in the eastern Luhansk region.
On Thursday, Kremlin spokesperson Dmitry Peskov also accused Kyiv of avoiding public peace negotiations.
'Dozens of bodies of torture victims' found in Kherson
Investigators in Ukraine's recently liberated southern Kherson region have uncovered 63 bodies with signs of torture after Russian forces left the area, according to reports quoting Ukraine's interior minister early on Thursday.
"The search has only just started so many more dungeons and burial places will be uncovered," Denys Monastyrsky reportedly told Ukrainian television.
Law enforcement bodies have uncovered 436 instances of war crimes during Russia's occupation, Monastyrsky added. Eleven places of detention were discovered, including four where torture had been practised.
"Investigators are currently examining them and setting down every instance of torture. Exhumations are also taking place of the bodies of those who were killed," Monastyrsky was quoted as saying.
Ukrainian and international investigators say what they describe as war crimes have been committed in areas occupied by Russian troops since Moscow's invasion of Ukraine in February.
Mass burial sites have been found in other parts previously occupied by Russian troops, including some with civilian bodies showing signs of torture.
On Sunday President Zelenskyy said investigators had uncovered more than 400 crimes in Kherson.
Russia denies its troops target civilians or have committed atrocities.
UN grain export deal extended for four months
The agreement on Ukrainian grain exports has been extended for four months to cover the winter months, authorities confirmed on Thursday.
Kyiv was the first to announce the renewal of the agreement "for 120 days".
Turkish President Recep Tayyip Erdogan confirmed that the renewal would be "under the same conditions" as those observed since July.
"I welcome the agreement by all parties to continue the Black Sea grain initiative to facilitate the safe navigation of export of grain, foodstuffs and fertilisers from Ukraine," UN Secretary-General Antonio Guterres said in a statement on Thursday.
The deal -- which involves Ukraine, Russia, Turkey, and the United Nations -- was due to expire at midnight on Friday. Over the past four months, it has allowed more than 11 million tonnes of agricultural to leave Ukrainian ports.
Erdogan, one of the architects of the agreement, had said on Wednesday he was "convinced" that the agreement would be renewed.
Zelenskyy set 'bad example' by blaming Russia for Poland blast, says Hungary
The Hungarian government has stated that Ukrainian President Zelenskyy set a "bad example" by claiming a missile that killed two people in a Polish border village was Russian.
Both Poland and NATO say it is highly likely that the rocket was a Ukrainian anti-aircraft device and that it had accidentally landed on Polish territory.
Zelenskyy has insisted that the missile was "Russian" and said on Wednesday that he had "no doubt" that it did not come from Ukraine.
Kyiv has also called for Ukrainian experts to have access to all data from the explosion site in Poland.
"In such a situation, world leaders speak responsibly," said Gergely Gulyas, chief of staff to Hungarian Prime Minister Viktor Orban.
"The Ukrainian president, by immediately accusing the Russians, was wrong, it's a bad example," he added.
But Gulyas echoed other NATO countries by stating that "only Russia" is responsible for the war in Ukraine.
"Without war, there would be no missile strikes in Poland," he told reporters.