KYIV, July 30 (Reuters) - The Ukrainian military said on Saturday it had killed scores of Russian soldiers in fighting in the south, including the Kherson region that is the focus of Kyiv's counter-offensive in that part of the country and a key link in Moscow's supply lines.
Rail traffic to Kherson over the Dnipro River had been cut, the military's southern command said, potentially further isolating Russian forces west of the river from supplies in occupied Crimea and the east.
Defence and intelligence officials from Britain, which has been one of Ukraine's staunchest allies in the West since Moscow's Feb. 24 invasion, portrayed Russian forces as struggling to maintain momentum.
Ukraine has used Western-supplied long-range missile systems to badly damage three bridges across the Dnipro in recent weeks, cutting off Kherson city and - in the assessment of British defence officials - leaving Russia's 49th Army stationed on the west bank of the river highly vulnerable.
The Ukrainian military's southern command said more than 100 Russian soldiers and seven tanks had been destroyed in fighting in the south on Friday.
The first deputy head of the Kherson regional council, Yuri Sobolevsky, told residents to stay from away from Russian ammunition dumps.
"The Ukrainian army is pouring it on against the Russians and this is only the beginning," Sobolevsky wrote on the Telegram app.
The pro-Ukrainian governor of Kherson region, Dmytro Butriy, said Berislav district was particularly hard hit. Berislav is across the river northwest of the Kakhovka hydroelectric power plant.
"In some villages, not a single home has been left intact, all infrastructure has been destroyed, people are living in cellars," Butriy wrote on Telegram.
Reuters could not independently verify the reports.
Officials from the Russian-appointed administration running the Kherson region earlier this week rejected Western and Ukrainian assessments of the situation.
In an intelligence update on Saturday, Britain's defence ministry said Russia had likely established two pontoon bridges and a ferry system to compensate for bridges damaged in Ukrainian strikes.
Russian-installed authorities in occupied territories in southern Ukraine were possibly preparing to hold referendums on joining Russia later this year, and were "likely coercing the population into disclosing personal details in order to compose voting registers," it added.
On Friday the ministry described the Russian government as "growing desperate", having lost tens of thousands of soldiers in the war. The chief of Britain's MI6 foreign intelligence agency, Richard Moore, added on Twitter that Russia is "running out of steam".
PRISON DEATHS
Ukraine and Russia have traded accusations over a missile strike or explosion that appeared to have killed dozens of Ukrainian prisoners of war in eastern Donetsk province. The incident took place early on Friday in the frontline town of Olenivka held by Moscow-backed separatists.
Russia's defence ministry on Saturday published a list of Ukrainian prisoners of war who it said were killed and wounded in what it said was a missile strike by the Ukrainian military. It said the strike by U.S.-made HIMARS rockets had killed 50 prisoners and injured another 73.
Ukraine's armed forces denied responsibility, saying Russian artillery had targeted the prison to hide the mistreatment of those held there. Foreign Minister Dmytro Kuleba said on Friday Russia had committed a war crime and called for international condemnation.
Reuters could not immediately verify the differing versions of events, but some of the deaths were confirmed by Reuters journalists who visited the prison.
U.S. Secretary of State Antony Blinken expressed his condolences over the deaths in a phone call on Friday with Kuleba, according to a State Department statement on Saturday.
The United States is committed to "hold Russia accountable for atrocities committed by its forces against the people of Ukraine," Blinken told Kuleba.
The United Nations is prepared to send a group of experts to Olenivka to investigate the incident, if it gets consent from both parties, U.N. spokesperson Farhan Haq said. The International Committee of the Red Cross said on Friday it was seeking access to the site and had offered to help evacuate the wounded.
Russian defence ministry spokesperson Igor Konashenkov said on Saturday that "all political, criminal and moral responsibility for the bloody massacre against Ukrainians falls on (Ukrainian President Volodymyr) Zelenskiy, his criminal regime and Washington who supports them".
A charity linked to Ukraine's Azov regiment said on Telegram it was not immediately able to confirm or deny the authenticity of the Russian list of people killed and wounded.
Ukraine has accused Russia of atrocities and brutality against civilians since its invasion and said it has identified more than 10,000 possible war crimes. Russia denies targeting civilians and has denied allegations of war crimes.
