As the story starts to turn from the explosions to the investigation, stay with VOA as we continue our coverage
. Nearly four hours after the blasts rocked the Boston Marathon, here is what VOA knows:
Two explosions near the finish line killed two people and wounded more than fifty. A third incident took place at the nearby John F. Kennedy library about 90 minutes later, but police are not sure if it is related to the marathon blasts.
President Obama says officals do not yet know who is responsible for the bombings, but that the U.S. will find out who did this and hold them accountable. No person or group has claimed responsiblity for the bombing.
This story is likely to dominate a lot of front pages around the world for several days.
Location of the marathon finish line in Boston, Massachusetts, where two deadly explosions occurred.
The London Marathon, which is scheduled to be held on Sunday, April 21, has released the following statement
We are deeply saddened and shocked by the news from Boston. Our immediate thoughts are with the people there and their families. It is a very sad day for athletics and for our friends and colleagues in marathon running.
Our security plan is developed jointly with the Metropolitan Police and we were in contact with them as soon as we heard the news.
Met Police Chief Superintendent Julia Pendry said: "A security plan is in place for the London Marathon. We will be reviewing our security arrangements in partnership with London Marathon."
More of President Obama's public statement:
Obama said he is directing the full resources of federal government to help state and local authorities to protect our people and increase security around the country.
He added, "We don’t yet have all the answers but we do know multiple people have been wounded, some gravely in the Boston marathon."
He said he has spoken with FBI director Muller and Homeland Security director Naplitano and that they are mobilizing resources to respond. He added that he has updated leaders of congress in both parties.
He said also said Boston police, firefighters and first responders as well as the national guard responded heroically and continue to do so as we speak.
"We still do not know who did this or why and people should not jump to conclusions without all the facts. We will get to the bottom of this. We will find out who did this and why they did this. Any responsible individual and responsible groups will feel the full weight of justice."
President Obama says they do not yet know who is responsible for the bombings, but that the U.S. will find out who did this and hold them accountable.
Watch the president's statement from the White House.
AT&T says it is leaving its WiFi on at the Boston Marathon.
Authorities now say two dead and at least 50 injured in the blasts.
President Obama will make an address from the press room at the White House in about 30 minutes. No further details have been released yet.
Boston police say to expect more visible security:
And people start seeing more security:
Google has started a person finder
for those looking for people who may have been at the Boston Marathon today.
The White House has released a photo
of President Obama on the phone with officials in Boston today.
New from the Boston police:
Via Computer World: A fixed camera captured the moment two explosions rocked the finish line of today's Boston Marathon.
Incredible video of the explosions as they happened from Boston.com
More from the police press conference:
Police may continue blowing things up (controled explosions) in next couple of hours.
Question: Is this a terrorist attack?
Answer from Boston Police Commissioner Edward Davis: "We're not being definitive at this time but you can reach your own conclusions."
From the Boston police department:
More from the Boston press conference:
From the police press conference in Boston:
Edward Davis, Boston Police Commissioner, says the blasts occurred 50 to 100 yards apart. Multiple casualties. All victims been removed from scene. Sent officers to hospitals to be in touch with family members and possible witnesses. Immediately activated system of resposnse that the commonwealth of Massachusettes has in place.
First calls were to FBI and state police.
There is a third incident, an explosion at the JFK Library. But authorities are not certain incidents are related. Recommending people stay home.
Anyone with information should call 1-800-494-TIPS
The FAA has imposed a no-fly zone over the site of the Boston Marathon explosions.
The White House says President Obama has called Boston Mayor Tom Menino and Massachusetts Governor Deval Patrick and told them his administration would provide whatever assistance is necessary in the investigation and response.
The New York Times just published a very useful graphic of the explosion locations
Meanwhile, New York City is stepping up security at various locations in response to the blasts in Boston.
At least one college in the Boston area is sending out alerts to its students.
More pictures of the aftermath from Twitter.
In a post on Facebook, Boston marathon says: "There were two bombs that exploded near the finish line in today's Boston Marathon. We are working with law enforcement to understand what exactly has happened."
Boston police say 2 are dead and 23 were injured by the explosions.
A spokeswoman for Massachusetts General Hospital said four patients were being treated there.
A New York City Police Department spokesman said the city has stepped up security around landmarks in Manhattan, including near prominent hotels, in response to the blast.
Here are some early pictures and video of the explosions.