Boston Marathon explosions killed at least two people and injured up to 60 after two large bombs went off near the finish line of the famous race, according to new reports.

Law enforcement sources told one newspaper that 12 people had been killed, but Boston police have only confirmed two dead. The sources added that the first explosion happened at the Fairmont Hotel.

Boston Marathon explosions killed at least two people and injured up to 60 after two large bombs went off near the finish line of the famous race

Boston Police Commissioner Edward Davis said at an afternoon press conference that there was a third, uncontrolled explosion at the JFK Library, though there were no injuries reported.

It is being reported that a Saudi-Arabian suspect is being held in custody at a Boston hospital on suspicion of involvement, though reports were quickly quashed by the Boston police department. A shadowy figure was also spotted on CCTV around 20 minutes before the bombs went off.

Eyewitnesses at the scene said there were two loud explosions about five seconds apart, and emergency vehicles crowded the scene.

Police told the Boston Globe that are they still finding “secondary devices”, and pleading with anyone still in the area to leave at once. A controlled explosion was set for outside the city library.

Sources told the New York Post that up to 12 people had been killed in the two blasts, and further reported that a suspect is in custody at a Boston-area hospital and is being closely guarded.

CBS News reports that police are now looking at surveillance video showing someone carrying multiple backpacks into the area about 20 minutes before explosions.

One witness said “there was blood everywhere”.

CNN revealed that families from last December’s Newtown tragedy were at the scene, though none of them were reported injured.

Boston’s Lenox Hotel that serves as the headquarters for the Boston Marathon was locked down on Monday after a security incident near the finish line. Two blasts were heard by reporters in the media center.

Authorities closed off the finish line and urged anyone in the area to stay away from trash bins.

In response to the attacks, both the White House and New York’s Times Square were given extra security measures. The White House released in a statement that President Barack Obama received a briefing from Homeland Security advisor Lisa Monaco and other members of his staff in the Oval Office.

“The president called Boston Mayor Tom Menino and expressed his concern for those who were injured and to make clear that his administration is ready to provide needed support as they respond to this incident.”

House of Representatives Speaker John Boehner is expected to lead a moment of silence in the House from the Speaker’s chair for the victims of the Boston bombing at around 6:30 p.m. EST, and the president is expected to speak at 6:10 p.m. EST.

Andrea Storer, who witnessed the blast, told the Boston Globe: “It was huge. There had to be people killed. There had to be.”

NECN reporter Jackie Bruno posted on Twitter: “I saw people’s legs blown off. Horrific. Two explosions. Runners were coming in and saw unspeakable horror.”

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