Methane Acta | Anadolu Agency | Getty Images Ukraine’s president warned that Russia could do something “particularly harsh” as Ukraine prepares to celebrate Independence Day on Wednesday – a day that also marks six months of Moscow’s invasion. In his late-night address on Saturday, President Volodymyr Zelenskyy called on Ukrainians to be strong and keep fighting as the country prepared to mark its independence from Soviet rule on August 24. “We should be aware that this week Russia might try to do something particularly bad, something particularly cruel,” he said without elaborating. He charged that one of Russia’s main goals is to “underestimate our capabilities” and spread despair, fear and conflict. “Therefore it is important never, not even for a moment, to yield to this hostile pressure, not to buckle, not to show weakness.” Ukraine will celebrate its 31st Independence Day on Wednesday — six months since Russia’s unprovoked invasion, described by Moscow as a “special military operation.” “An important milestone is ahead – six months of this large-scale invasion,” Zelensky said in his video message, calling it “the war that changed everything for Ukraine, for Europe and for the world.” According to the United Nations Human Rights Office, more than 5,500 civilians in Ukraine have been killed and nearly 7,700 civilians injured since the start of the war until August 15. “Most recorded civilian casualties were caused by the use of explosive weapons with wide-area effects, including heavy artillery shelling, multiple launch rocket systems, rockets and airstrikes,” according to the Office of the United Nations High Commissioner for Human Rights. . Separately, Russian state media accused Ukrainian forces of firing artillery at the Zaporizhzhia nuclear power plant in Ukraine, Europe’s largest nuclear power plant. Located in the southeastern town of Enerhodar, the nuclear power plant was seized by Moscow at the beginning of the war. Russian state news agency RIA Novosti reported that Ukraine’s armed forces have regularly attacked the Zaporizhia facility in recent weeks, risking a large-scale nuclear disaster. Both Russia and Ukraine have repeatedly accused each other of bombing the power plant. NBC News reported that the headquarters of Russia’s Black Sea Fleet in annexed Crimea was hit by a drone early Saturday. The Russian Black Sea Fleet is headquartered in Sevastopol, Crimea, which was annexed by Moscow in 2014. “A drone flew into the roof,” the Russian-appointed governor of occupied Crimea, Mikhail Razvozhayev, said on Telegram. NBC News was unable to independently verify the photos and a video posted online that appeared to show a plume of smoke rising from the fleet’s headquarters.