A third potential bomb explosion has been confirmed at JFK Library in Boston, according to authorities. Earlier, just before 3 p.m. two large bomb explosions were seen at the Boston Marathon route near the finish line, killing at least 2 and injuring at least 100 others, including as many as 6 in critical condition.
At a new conference held just before 5 p.m. ET, Boston Police Commissioner Ed Davis, confirmed that three explosive devices have hit Boston Monday afternoon; two at the marathon and a third at JFK Library. That third device has not been confirmed as being related to those at the marathon, but authorities have said they are treating it as if it is related.
Earlier reports of a fourth device were not confirmed at that time, however, soon after an update was given suggesting that the injury toll has risen to at least 100 people, according to The Boston Globe at about 5.10 p.m. ET.
The devastating scenes at the Boston Marathon have shown injured people being carried away from the scene of the explosions, which took place near the finish line of the marathon route.
Witnesses reported that two loud bangs were heard near the finish line, and video footage can be seen at the moment of the explosions with a big fireball seen coming from one of the buildings to the side of the road.
The two explosions at the marathon were heard about 10 to 15 seconds apart, with some reports describing a ball of flames coming out from the Marathon Sports store near the finish line.
Other early reports are claiming more injuries are expected to be reported. Some reports have claimed that some bloodied victims were taken to a medical tent for treatment, and many others have been taken to hospital. Some of those being treated in hospital are said to have suffered critical injuries and have been taken immediately to the emergency room.
Early video footage has shown chaotic scenes at the location, with some people being blown off their feet when the explosion took place, and massive amounts of smoke seen filling the streets where the explosions hit.
Huge amounts of smoke could be seen coming from the Marathon Sports store and marathon officials were seen pulling at some metal railings that were twisted and piled on the ground, seemingly to free some people under them.
Other eye witnesses reported a bloody scene, with some victims being very seriously injured near the scenes of the explosions.
Police are being deployed to major landmarks in other large cities across the United States, including New York City, as fears of a possible terrorist attack emerge.
President Obama has been notified and he will now remain in constant contact with officials at the scene and has promised to offer any assistance needed in the aftermath of the incident.
Here is video footage in the aftermath of the bombings: