Bitter fighting raged in Sievierodonetsk, but the region's governor said Ukraine remained in control of an industrial area and chemical plant in the eastern city where hundreds of civilians are sheltering from incessant Russian shelling.
A Russia-backed separatist group on Saturday claimed 300 to 400 Ukrainian fighters were also trapped at the Azot plant.
Earlier, the governor, Serhiy Gaidai, conceded Russian forces now controlled most of the small city in Luhansk province, and said Russian shelling of the plant had ignited a big fire after an oil leak. It was not known if the fire was still burning on Sunday.
In neighbouring Donetsk province to the west, Russian media reported a huge cloud of smoke could be seen after an explosion in the city of Avdiivka, which houses another chemical plant.
FILE PHOTO: Black smoke billows over Sievierodonetsk Azot chemical plant as Russia's invasion on Ukraine continues, in Sievierodonetsk, Luhansk Region, Ukraine.
LUHANSK REGION POLICE
Sievierodonetsk has become epicentre of the battle in eastern Ukraine for control over the industrialised Donbas region, made up of the Luhansk and Donetsk provinces. Weeks of fighting has pulverised parts of the city and has been some of the bloodiest since Moscow began its invasion on Feb. 24.
After being forced to scale back its initial campaign goals, including withdrawing troops that had been menacing Kyiv, Moscow has turned to expanding control in the Donbas, where pro-Russian separatists have held a swath of territory since 2014.
Putin calls the invasion a "special military operation" to disarm and "denazify" Ukraine. Kyiv and its allies call it an unprovoked war of aggression to capture territory.
"The information about the blockade of the Azot plant is a lie," Gaidai said on the Telegram messaging app. "Our forces are holding an industrial zone of Sievierodonetsk and are destroying the Russian army in the town."
Ukraine has said some 800 people were hiding in bomb shelters under the plant, including employees and residents of Sievierodonetsk.
Rodion Miroshnik, a Russian-backed representative of the self-proclaimed Luhansk People's Republic, said Ukrainian forces may be holding several hundred civilians "hostage".
Ukraine's armed forces said they had pushed back a Russian attack on three small towns northwest of Sloviansk in Donetsk province, while fighting continued in a fourth settlement in the area, as well as to the east of the city.
In a video address, Ukrainian President Volodymyr Zelenskiy said that Ukrainian military was gradually liberating territory further west in the Kherson region and had had some successes in Zaporizhzhia.
"We are definitely going to prevail in this war that Russia has started," he told a conference in Singapore by video link. "It is on the battlefields in Ukraine that the future rules of this world are being decided."
Reuters could not independently verify the battlefield reports.
Local resident Viacheslav walks on debris of a residential building damaged by a military strike, as Russia's attack on Ukraine continues, in Sievierodonetsk, Luhansk region, Ukraine.
SERHII NUZHNENKO
Ukraine has appealed for swifter deliveries of heavy weapons from the West to turn the tide of the war.
Ukrainian forces have proven more resilient than expected, but the U.S.-based Institute for the Study of War said that as they use the last of their stocks of Soviet-era weapons and munitions, they will require consistent Western support.
Pavlo Kyrylenko, the Donetsk governor, said two civilians were killed in Russian shelling on Saturday and at least 10 wounded.
In the northeastern city of Kharkiv, some students returned to their destroyed school to hold a prom, dancing and posing for pictures in the ruins.
German Chancellor Olaf Scholz, French President Emmanuel Macron and Italian Prime Minister Mario Draghi will visit Kyiv before a Group of Seven summit at the end of June, Germany's Bild am Sonntag newspaper reported, citing French and Ukrainian government sources.
None of the three has been to Kyiv since Russia's invasion. Macron has sought to maintain a dialogue with Russian President Vladimir Putin, a stance some eastern European and Baltic countries see as undermining efforts to push him into negotiations.
European Commission President Ursula von der Leyen said the European Union executive's opinion on Ukraine's request to join the EU would be ready in the coming week.
All 27 EU governments would have to agree to grant Ukraine candidate status, after which there would be extensive talks on reforms required before the country could be considered for membership.
Volodymyr Trush, governor of the Ternopil region in western Ukraine, said on Saturday evening there was a Russian airstrike in the area of the city of Chortkiv. Russian planes had not attacked the area since early April.
Local authorities cut off natural gas while working with “the consequences of the explosion", Trush said, but did not elaborate. The mayor of Chortkiv urged all residents to remain in shelters.
