Ukraine war latest: Russia plans to strike President's Office, Zelensky says (opens in new tab)

Key developments on May 15: * Russia plans to strike President's Office building and state residence, Zelensky says * Massive fire erupts at Russia's Ryazan oil refinery as Ukrainian drone blitz hits multiple targets, oblasts * 205 Ukrainian POWs return from Russian captivity in latest exchange * Russia plans to attack Ukraine or NATO from Belarus, Zelensky says * Russian military unit documents own war crime, milblogger publishes then deletes video * Zelensky pays respects to victims of