BOSTON -- A Boston post office was evacuated on Thursday after a man left a box that he said contained a bomb on the counter.

Boston police said they were called to the post office on Avenue De Lafayette at about 3:30 p.m. According to the Postal Service, a man in his 50s with a gray beard put a box on the counter. When the postal clerk asked how he wanted to mail the box, and he told her to read a note.

The Postal Service said the note read, "This is a bomb. Put your 20s and 50s in the box or I'll blow this place up."

The clerk gave the man all the money she had, about $40, and he ran out, leaving the box on the counter.

Streets in the immediate area were blocked off and motorists were asked to seek alternate routes.

NewsCenter 5 and TheBostonChannel.com will have more details as they become available.