Kharkiv (Ukraine) (AFP) – Ukrainian President Volodymyr Zelensky made his first trip Sunday to the war-torn east since Moscow’s invasion started, as Russian forces tightened their grip around key cities in the Donbas region. After visiting Kharkiv, Zelensky announced that he had fired the northeastern city’s security chief in a rare public rebuke. Zelensky said the man was dismissed “for not working to defend the city from the first days of the full-scale war, but thinking only of himself,” and that while others had toiled “very effectively”, the former chief had not. Although the president di…