Police advise people to stay indoors, visitors to return to hotel rooms and everyone to avoid crowds
Boston police confirm at least 2 dead and more than 100 injured
No suspects have been arrested; no one has claimed responsibility for blasts
Boston say 2 simultaneous blasts occurred near finish line
Fire at nearby JFK Library is not confirmed to be related to marathon blasts
Intelligence official tells the AP 2 more explosives were located and dismantled
NYC has beefed up security in response to the blasts
2 bombs exploded under stands just before the mile 26 marker near the finish line
President Obama debriefed and ready to provide whatever support needed
FAA orders no-fly zone over Boston explosion site
UK will review plan to host London Marathon slated for 4/21
