Russian troops are in the southern Ukrainian city of Kherson and forced their way into the council building, the mayor said after a day of conflicting claims over whether Moscow had made the first major gain of a city in its eight-day-long invasion. The Black Sea port of Kherson, a southern provincial capital of around 250,000 people, is strategically placed where the Dnipro River flows into the Black Sea and would be the first significant city to fall into Moscow’s hands. Russia’s defence ministry said on Wednesday morning it had captured Kherson but several hours later an adviser to Presiden…