By Emma Farge GENEVA (Reuters) -A World Food Programme (WFP) official said on Friday that food supply chains in Ukraine were collapsing, with key infrastructure such as bridges and trains destroyed by bombs and many grocery stores and warehouses empty. Jakob Kern, WFP Emergency Coordinator for the Ukraine crisis, expressed concern about the situation in “encircled cities” such as Mariupol, saying that food and water supplies were running out and that its convoys had been unable to enter. “The country’s food supply chain is falling apart. Movements of goods have slowed down due to insecurity an…