SKYY News says there was a third explosion at JFK library.
http://news.sky.com/story/1078597/boston-marathon-explosions-third-blast
The JFK library is about 4 miles from downtown Boston.
A lot of bombings in Iraq.
http://hosted.ap.org/dynamic/stories/M/ML_IRAQ?SITE=VAROA&SECTION=HOME&TEMPLATE=DEFAULT
IIRC, the Bomb Squad had a controlled detonation at a library.