By Anna Voitenko and Max Hunder
CHASIV YAR/KYIV, Ukraine (Reuters) -At least 15 people were killed and two dozen more were feared trapped after Russian rockets hit a five-story apartment block in Ukraine's eastern Donetsk region, local officials said on Sunday as rescuers picked their way through rubble.
Ukraine also reported clashes with Russian troops on fronts in the east and south, while Moscow said its forces struck Ukrainian army hangars storing U.S.-produced M777 howitzers, a type of artillery, near Kostyantynivka in Donetsk region.
Donetsk Governor Pavlo Kyrylenko said the strike on the apartment building took place on Saturday evening in the town of Chasiv Yar. The regional emergency service gave the death toll at 15 on Sunday afternoon.
Kyrylo Tymoshenko, deputy head of Ukraine's presidential office, wrote on Telegram that six people had been rescued from the rubble at Chasiv Yar, and that 23 people, including a child, remained buried.
"We ran to the basement, there were three hits, the first somewhere in the kitchen," said a local resident who gave her name as Ludmila, speaking as rescuers removed a body in a white sheet and cleared rubble using a crane as well as their hands.
"The second, I do not even remember, there was lightning, we ran towards the second entrance and then straight into the basement. We sat there all night until this morning." Another survivor, who gave her name as Venera, said she had wanted to save her two kittens.
"I was thrown into the bathroom, it was all chaos, I was in shock, all covered in blood," she said, crying. "By the time I left the bathroom, the room was full up of rubble, three floors fell down. I never found the kittens under the rubble."
FIGHTING FOR TERRITORY
Andriy Yermak, chief of staff to President Volodymyr Zelenskiy, said in a Telegram post that the strike was "another terrorist attack," and Russia should be designated as a state sponsor of terrorism as a result.
Russia, which says it is conducting a "special military operation" to demilitarize Ukraine, denies deliberately attacking civilians.
Luhansk and Donetsk provinces comprise the Donbas, Ukraine's eastern industrial region that has become Europe's biggest battlefield in generations. Russia wants to wrest control of the Donbas on behalf of the separatists that it supports.
Ukraine and the West - which has been supporting Ukraine with weapons and stiff sanctions on Russia - call Moscow's invasion an unprovoked war of aggression.
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 near the village of Bilohorivka, about 50 km (30 miles) east of Sloviansk.
Russia 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.
Russia claimed control over all of Luhansk province last weekend.
Russia's defence ministry said its forces had destroyed two hangars near the Donetsk town of Kostyantynivka holding the U.S.-made M777 howitzers, which it said had been used to shell residential areas of Donetsk.
Russian news agencies quoted separatist officials as saying on Sunday that Ukraine's military had been shelling Donetsk using NATO-standard 155-mm artillery since the morning, wounding two residents.
Reuters could not independently verify battlefield accounts.
Ukrainian military spokespeople were not immediately available for comment.
In the south, Ukrainian forces fired missiles and artillery at Russian positions, including ammunition depots in the Chornobaivka area, Ukraine's military command said.
Ukrainian Deputy Prime Minister Iryna Vereshchuk warned civilians in the Russian-occupied Kherson region on Sunday to urgently evacuate as Ukraine's armed forces were preparing a counter-attack there, not giving a timeframe for action.
"I know for sure that there should not be women and children there, and that they should not become human shields," she said on national television.
(Reporting by Max Hunder in Kyiv and Reuters bureaus; Writing by Robert Birsel, William Maclean and Patricia Zengerle;Editing by Pravin Char, Alex Richardson, Frances Kerry and Aurora Ellis)