MINNEAPOLIS, Feb. 8 (UPI) -- Eight U.S. post offices in southern Minnesota remain on alert after receiving letters the buildings would be bombed, authorities say.
The letters sent last week to postmasters warned bombs would be placed in the buildings as "part of a succession of eight post office bombing incidents," the Minneapolis Star Tribune reported Sunday.
A search of the offices found nothing unusual, but employees remain on alert, said Jeff Long a spokesman for the U.S. Postal Inspection Service.
The letters were sent to post offices in Mankato, North Mankato, St. James, Lake Crystal, Madelia, New Ulm, Sleepy Eye and Le Center.