At least six people were killed and more than 30 are feared trapped after Russian Uragan rockets hit a five-storey apartment block in Ukraine's Donetsk region, leading to the building collapsing, the region's governor said on Sunday.
Ukraine also reported clashes with Russian troops on fronts in the east and south, as the United States sought to marshal international support in opposing Moscow's invasion.
Donetsk Governor Pavlo Kyrylenko said the strike on the apartment building took place on Saturday evening in the town of Chasiv Yar. He said six people had been confirmed killed and five wounded. According to information from residents, at least 34 people are likely trapped in the ruins, he said on the Telegram messaging channel.
Russia, which says it is conducting a "special military operation" to demilitarise Ukraine, denies deliberately attacking civilians.
Luhansk and Donetsk provinces, parts of which were held by pro-Russian separatists before the conflict began in February, comprise the eastern industrial region of the Donbas that Russia is seeking to take over.
Russian forces attacked Ukrainian positions near the town of Sloviansk in Donetsk but were forced to withdraw, Ukraine's military said, adding that Russian forces had launched a cruise missile attack on the northeastern city of Kharkiv from their side of the border. It gave no details of damage or casualties.
Luhansk region Governor Serhiy Gaidai said Russian forces were gathering in the area of the village of Bilohorivka, about 50 km (30 miles) east of Sloviansk.
"The enemy is ... shelling the surrounding settlements, carrying out air strikes, but it is still unable to quickly occupy the entire Luhansk region," he said on Telegram.
"During the last night alone, the Russians launched seven artillery barrages and four rocket strikes."
Russia claimed control over all of Luhansk province last weekend.
Russia's Tass news agency, meanwhile, cited pro-Russian separatists as saying Ukrainian forces had fired an artillery barrage into residential districts of the city of Donetsk.
Ukrainian military spokesman were not immediately available for comment.
President Volodymyr Zelenskiy said on Saturday the Russian army had attacked civilians on purpose.
Russia sent tens of thousands of troops into Ukraine on February 24 in what it called a "special operation" to degrade its military capabilities and root out what it calls dangerous nationalists. Kyiv and its Western allies call the invasion an unprovoked land grab.
Ukrainian forces have mounted stiff resistance and the West has imposed sweeping sanctions on Russia in an effort to force it to withdraw.
In the south, Ukrainian forces fired missiles and artillery at Russian positions including ammunition depots in the Chornobaivka area, Ukraine's military command said.
