Fighting around the city of Sievierodonetsk has intensified, with at least 1,500 casualties and 60% of residential buildings destroyed. About 12,000 to 13,000 people remain in the city, according to the local mayor, with Sievierodonetsk the only part of the Luhansk region in Donbas still under Ukrainian government control. Elsewhere, two Russian soldiers accused of war crimes have appeared at a second trial hearing in the northeastern town of Kotelva, while Ukrainian President Volodymyr Zelensky pleaded with the West on Thursday to send multiple launch rocket systems to Ukraine as soon as possible. Pro-Russian separatists from the self-proclaimed Donetsk People's Republic said on Friday that they have established full control over the strategic town of Lyman in eastern Ukraine. Ukrainian and Russian forces had been fighting for the Donbas region town for several days. Superyacht in Fiji The United States has won the latest round of a legal battle to seize a $325-million Russian-owned superyacht in Fiji, with the case now appearing headed for the Pacific nation's top court. The case has highlighted the thorny legal ground the US finds itself on as it tries to seize assets of Russian oligarchs around the world. Those intentions are welcomed by many governments and citizens who oppose the war in Ukraine, but some actions are raising questions about how far US jurisdiction extends. Fiji's Court of Appeal on Friday dismissed an appeal by Feizal Haniff, who represents the company that legally owns the superyacht Amadea. Haniff had argued the US had no jurisdiction under Fiji's mutual assistance laws to seize the vessel, at least until a court sorted out who really owned the Amadea. Haniff said he now plans to take the case to Fiji's Supreme Court and will apply for a court order to stop U.S. agents sailing the Amadea from Fiji before the appeal is heard. Civilian deaths mount At least five civilians have been killed in 24 hours in the Lugansk region in eastern Ukraine, the epicentre of fierce fighting with Russian troops, regional governor Sergei Gaïdaï announced on Friday morning. Four civilians were killed in Severodonetsk, a regional capital under the control of the Ukrainian authorities that the Russians are seeking to conquer, and 50 buildings were damaged there, he said. A man was also killed by a shell in Komychouvakha, 50 kilometres from Severodonetsk. "The people of Severodonetsk have forgotten what a ceasefire for at least half an hour is," Sergey Gaidai wrote on Telegram. "The Russians are constantly shelling the residential areas". Pavlo Kyrylenko, governor of Donetsk, another region of Donbas, reported Thursday evening five civilians killed during the day. Zelensky accused Russia of carrying out "genocide" in his nightly address on Thursday evening. "The current occupiers' offensive in Donbas could empty the region of its inhabitants," Zelenskyy said, accusing the invaders of seeking to "burn down" Severodonetsk and other towns in the region. Russian forces are carrying out "deportations" and "mass killings of civilians" in the Donbas, he continued, denouncing "an obvious policy of genocide carried out by Russia". Meanwhile, Washington held discussions with Kyiv about the danger of escalation if it strikes deep inside Russia, US and diplomatic officials told Reuters. The behind-the-scenes discussions, which are highly sensitive and have not been previously reported, do not put explicit geographic restrictions on the use of weapons supplied to Ukrainian forces. But the conversations have sought to reach a shared understanding of the risk of escalation, three US officials and diplomatic sources said. "We have concerns about escalation and yet still do not want to put geographic limits or tie their hands too much with the stuff we're giving them," said one of the three US officials, speaking on condition of anonymity. After initially forecasting Ukraine would be overrun by Russia's much bigger military, American officials have recently voiced hopes that Ukrainian forces can win the war, and want to arm them to do so. US officials say the Biden administration is even considering supplying Kyiv with the M142 High Mobility Artillery Rocket System (HIMARS), which depending on the munitions can have a range of hundreds of kilometres. A second US official, also speaking on condition of anonymity, said Washington and Kyiv had a shared "understanding" about the use of certain Western-provided weapon systems. "So far, we've been on the same page about the thresholds," the official said. Russian Foreign Minister Sergei Lavrov warned the West that supplying weapons to Ukraine capable of hitting Russian territory would be "a serious step towards unacceptable escalation," according to remarks published on the Russian foreign ministry website on Thursday. — Agencies