By Natalia Zinets and Max Hunder KYIV (Reuters) – Russian forces captured territory along a frontline river in eastern Ukraine on Monday and President Volodymyr Zelenskiy predicted Moscow would escalate attacks ahead of a summit of European leaders expected to welcome Kyiv’s bid to join the EU. Moscow’s separatist proxies claimed to have captured Toshkivka, a town on the mostly Ukrainian-held western bank of the Siverskyi Donets river, south of Sievierodonetsk, which has become the main battlefield city in recent weeks. Ukraine acknowledged that Moscow had success in Toshkivka and said the Rus…