Russia claimed on Sunday to have captured the strategic Ukrainian city of Lysychansk and the entire frontline Lugansk region which would mark a decisive breakthrough for Moscow's forces seeking control of the country's east.
The development came as Belarus said it had intercepted missiles fired by Kyiv and Russia reported that Ukraine launched three cluster missiles at Belgorod, killing four people.
Lysychansk had been the last major city in the Lugansk area of the eastern Donbas still in Ukrainian hands and its capture would signal a deeper push into the Donbas, Moscow's focus since retreating from Kyiv.
On Saturday, there were conflicting reports about Lysychansk's status with Ukraine denying Moscow's claim to have encircled the entire city, located across the river from neighbouring Severodonetsk which Russian forces seized last week.
Ukraine has yet to comment on the claim that Lysychansk has fallen following days of intense clashes.
"Sergei Shoigu has informed the commander in chief of the Russian armed forces, Vladimir Putin, of the liberation of the People's Republic of Lugansk," the defence ministry said in a statement quoted by Russian news agencies.
A few minutes prior to the announcement, which AFP has not verified, a spokesman for the Russian defence ministry had said fighting was ongoing in Lysychansk and that Ukrainian forces were "completely" surrounded.
- Russian city struck -
Russia's claim of a breakthrough came as Moscow said Sunday its anti-aircraft defences shot down three Tochka-U cluster missiles launched by "Ukrainian nationalists" against Belgorod, close to the Ukrainian border.
Belgorod governor Vyacheslav Gladkov said 11 residential buildings and 39 houses were damaged.
Russia has previously accused Kyiv of conducting strikes on Russian soil, particularly in the Belgorod region.
Separately, Belarusian leader Alexander Lukashenko accused Kyiv of "provoking" his country and said his army intercepted missiles fired at his country by Ukrainian forces "around three days ago".
Belarus is a long-term Russian ally that supported the February 24 invasion and has been accused by Kyiv of launching its own attacks on Ukrainian territory.
But Lukashenko denied any involvement in a recent cross-border incident, which would represent an escalation of the conflict.
"As I said more than a year ago, we do not intend to fight in Ukraine," he was quoted as saying by state news agency Belta on Saturday.
- 'Fierce fighting' -
Missiles continued to rain down across Ukraine, killing dozens, and fierce fighting continued according to Ukrainian President Volodymyr Zelensky.
"Fierce fighting continues along the entire front line, in Donbas," he said in an address late Saturday, adding that "enemy activity in the Kharkiv region is intensifying".
In the small Donetsk town of Siversk, one resident told AFP that "the bombing goes on day and night".
Two people were killed and three wounded -- including two children -- in a strike on the town of Dobropillya, local authorities in Donetsk said.
Rockets also struck residential properties in Sloviansk in the heart of the Donbas, killing a woman in her garden and wounding her husband, a neighbour told AFP Saturday, describing debris showered across the neighbourhood.
The witness said the strike, which took place on Friday, was thought to use cluster munitions, which spread over a large area before exploding, striking buildings and people who were outdoors.
Zelensky warned against complacency in cities that have been spared the violence seen in others.
"The war is not over," he said.
"Unfortunately, its cruelty is only increasing in some places, and it cannot be forgotten."
In his address, Zelensky also spoke about a conference on Ukraine's reconstruction set to start Monday in Switzerland.
Leaders from dozens of countries and international organisations will gather in the city of Lugano with the aim of providing a roadmap for the war-ravaged country's recovery.
Rebuilding Ukraine "requires colossal investments -- billions, new technologies, best practices, new institutions and, of course, reforms," Zelensky said.
He said 10 regions of Ukraine had been affected in the war, with many towns and villages needing to be "rebuilt from scratch".
The roadmap is expected to lay out reconstruction needs including damaged and destroyed infrastructure, Ukraine's devastated economy, and also environmental and social needs.
The effort is expected to cost hundreds of billions of dollars.
Ukraine will also face demands for broad reforms, especially in cracking down on corruption.
The need for reforms had been underscored by European Commission, Ursula von der Leyen, who has said the coveted European Union membership was "within reach" for Ukraine, but urged Kyiv to work on anti-corruption measures.
In peacetime, Ukraine is a major agricultural exporter, but Russia's invasion has damaged farmland and seen Ukraine's ports seized, razed or blockaded -- sparking concerns about food shortages, particularly in poor countries.
Farmer Sergiy Lyubarsky, whose fields are close to the frontline, warned time was running out to harvest this year's crop.
"We can wait until August 10 at the latest, but after that, the grains are going to dry out and fall to the ground," he said.
Western powers have accused Putin of using the trapped harvest as a weapon to increase pressure on the international community, and Russia has been accused of stealing grain.