Homeland Security Secretary Janet Napolitano says there is no evidence that the bombings at the Boston Marathon are part of a wider plot.
Napolitano says DHS will maintain what she called "enhanced security measures at transportation hubs" as a precaution.
Two people briefed on the investigation tell The Associated Press that a pair of bombs packed into pressure cookers and concealed in duffel bags blew up within seconds of each other.
Source: AP. Read full article. (link)