Economic activity strengthened in most U.S. regions during March and early April with the exception of St. Louis, where plans to close several plants were announced, the Federal Reserve said on Wednesday.

Overall economic activity increased somewhat...across all Federal Reserve districts except St. Louis, which reported 'softened' economic conditions, the Beige Book summary prepared by the Minneapolis regional Fed bank said.

(Reporting by Glenn Somerville, Editing by Chizu Nomiyama)