After Russian President Vladimir Putin ordered his invading army to attack \u0022from all directions,\u0022 Ukraine\u0026#039;s defense forces and civilian volunteers reportedly repelled an assault on Kharkiv, the country\u0026#039;s second-largest city, but battles remain underway nationwide on Sunday as diplomatic efforts unfold.\r\n\r\nUkrainian President Volodymyr Zelenskyy announced Sunday that Kyiv\u0026nbsp;intends to send a delegation to the Ukraine-Belarus border to hold discussions with Moscow \u0022without preconditions.\u0022\r\n\r\nZelenskyy rejected Putin\u0026#039;s earlier offer to meet his delegation in Minsk—saying that talks there could have been possible had Russia not attacked Ukraine from Belarus—but agreed after Belarusian President Alexander Lukashenko assured him during a phone call that \u0022all planes, helicopters, and missiles stationed on Belarusian territory remain on the ground during the Ukrainian delegation\u0026#039;s travel, talks, and return\u0022 from the border.\r\n\r\nJust before the planned negotiations were announced,\u0026nbsp;Putin ordered the Russian military to put its nuclear forces on \u0022special alert.\u0022\r\n\r\nThe move, made in response to what Putin called \u0022aggressive statements\u0022 by members of the North Atlantic Treaty Organization (NATO), makes it easier to launch nuclear weapons more quickly, though it doesn\u0026#039;t necessarily mean that Russia intends to use them.\r\n\r\nAccording to BBC security correspondent Gordon Corera, Putin is likely trying to \u0022deter NATO support for Ukraine by creating fears over how far he is willing to go and creating ambiguity over what kind of support for Ukraine he will consider to be too much.\u0022\r\n\r\nEarlier Sunday, regional governor Oleh Sinegubov said that Ukrainian forces successfully expelled Russian troops following intense street fighting and are in full control of Kharkiv, a city roughly 300 miles east of the capital of Kiev, which is also still in Ukraine\u0026#039;s hands.\r\n\r\nOne video, verified by the BBC, shows a group of Ukrainian soldiers taking cover and launching missiles at Russian military vehicles in Kharkiv.\r\n\r\n\r\n\r\nThe BBC reported on overnight developments:\r\n\r\n\r\nResidents described intense shelling, with one woman saying it was \u0022something like Star Wars above your head.\u0022\r\n\r\nA nine-story residential tower was hit, emergency services said.\r\n\r\nThe building was severely damaged and an elderly woman was killed, according to emergency services. Rescuers said about 60 people were spared injury as they had taken refuge in the basement.\r\n\r\n\r\nUkrainian government ombudsman Lyudmyla Denysova said Sunday that more than 210 Ukrainian civilians have been killed and more than 1,100 wounded since the start of Russia\u0026#039;s invasion.\r\n\r\n\u0022With unseen cruelty, the enemy is destroying residential buildings, hospitals, kindergartens, and schools, taking away the right to live from the sons and daughters of Ukrainian land, including children,\u0022 she said in a social media post, according to the BBC.\r\n\r\nRussia should be \u0022punished severely for these crimes,\u0022 added Denysova. \u0022Ukraine is noting down all these facts and will pass them on to the military tribunal in The Hague.\u0022\r\n\r\nDamage to homes and critical infrastructure has left hundreds of thousands of people in Ukraine without access to water and electricity, according to the United Nations Office for the Coordination of Humanitarian Affairs.\r\n\r\nRussian forces blew up a gas pipeline in Kharkiv hours after bombing an oil terminal in Vasylkiv, 18 miles south of Kyiv, resulting in a huge explosion and toxic air warnings.\r\n\r\nThe residents of Kyiv, where fighting continues, have been directed by mayor Vitali Klitschko to remain underground, and a curfew is currently in place through 8 a.m. on Monday.\r\n\r\n\r\n\r\nUkraine\u0026#039;s deputy defense minister Hanna Malyar estimated Sunday that 4,300 Russian soldiers have been killed and dozens of pieces of military equipment—including planes, helicopters, tanks, armored vehicles, and cannons—destroyed since Putin ordered a full-scale invasion four days ago.\r\n\r\n\u0022Ukrainian civilians have also been attempting to block the advance of Russian forces peacefully,\u0022 the BBC reported. \u0022One video, believed to be recorded in the Chernihiv region, shows local residents halting a convoy of Russian tanks by walking at them en masse.\u0022\r\n\r\n\r\n\r\nThe number of people who have fled Ukraine to Poland, Hungary, Romania, Moldova, and other nations has grown to 368,000, according to U.N. High Commissioner for Refugees Filippo Grandi. They are mostly women and children, as Ukrainian men aged 18 to 60 are ordered to stay and fight.