GENEVA (Reuters) - Several thousand Ukrainians have crossed into neighbouring countries, mainly Moldova and Romania, while an estimated 100,000 have fled their homes and are uprooted in the country after Russia's invasion, the U.N. refugee agency said on Thursday.

       Shabia Mantoo, spokesperson of the U.N. High Commissioner for Refugees (UNHCR), said the figures were compiled from reports from national authorities and its staff and partner agencies. "It's a ballpark figure," she told Reuters.

       (Reporting by Stephanie Nebehay; Editing by Chris Reese)