U.S. hikes security at federal facilities after Tennessee shooting

WASHINGTON (Reuters) - U.S. authorities are increasing security at federal facilities "out of an abundance of caution" after a shooting on Thursday in Chattanooga, Tennessee, that killed four Marines, Homeland Security Secretary Jeh Johnson said. The Department of Homeland Security is closely monitoring the shooting and supporting the FBI investigation, Johnson said in a statement. He cautioned "there are many unconfirmed and possibly false reports about events." (Reporting by Doina Chiacu; Editing by Sandra Maler)