In pictures: Boston Marathon bombing- several die and more than 130 injured (23pics)
At least three people have been killed and another 100 maimed or injured after two powerful bombs were detonated at the finish line of the Boston marathon. The co-ordinated blasts, the worst attack on US soil since the September 11 terror atrocities, transformed a site of celebration on a public holiday afternoon into a scene of carnage and destruction. This is the moment one of the bombs detonated near the finish line of the Boston Marathon.
Several of the victims lost limbs and suffered horrific injuries as the twin blasts exploded about 30 seconds apart, some 50-100 yards away from each other near the finishing line of one of the world’s most prestigious sporting events.
A Boston Marathon competitor and police officers run from the area of the explosion near the finish line
Bill Iffrig fell when one of the bombs detonated. Shortly afterwards he got up and finished the race.
A runner and race officials react as the bomb explodes near the finish line of the Boston Marathon
There were unconfirmed claims that a wounded man was under guard in hospital as a “possible suspect”, but police later said that no suspect was in custody
Bystanders help an injured woman at the scene of the first explosion on Boylston Street near the finish line of the Boston Marathon
A person who was injured in an explosion near the finish line of the Boston Marathon is taken away from the scene in a wheelchair
A man is loaded into an ambulance after he was injured by one of two bombs exploded during the Boston Marathon
Airspace near the scene was closed down as security officials put counter-terror plans into place
Runner John Ounao crys after he finds friends after several explosions rocked the finish of the Boston Marathon
First responders rush to help injured people after two explosions occurred along the final stretch of the Boston Marathon
People assist an injured man after the explosion at the Boston Marathon in Boston
Medical workers aid injured people at the finish line of the Boston Marathon
Authorities were checking all bags and packages that may have been left unattended as crowds rushed away from the scene of the bombings. Above, bags containing marathon runners' belongings near the finish line of the Boston Marathon.
President Barack Obama has called officials in Massachusetts to express his sympathy and offer the support of the federal government after being briefed on the incident by Lisa Monaco, his new national security adviser.
Addressing the nation, Mr Obama said: “Make no mistake we will get to the bottom of this and we will find out who did this and we will find out why they did this. Any responsible groups will feel the full weight of justice. “The American people will say a prayer for Boston tonight and Michelle and I send our prayers to the families of the victims in the wake of this senseless loss.”
The Navy sent one of its bomb-disposal units to Boston after state officials asked for help
The aftermath of one of the two explosions near the finish of the Boston Marathon
A Swat team secure the main entrance to Bringham and Women's Hospital in Boston. Many who were wounded when two explosions struck near the finish line of the Boston Marathon were brought to Bringham and Women's.
Investigators at one of the blast sites on Boylston Street near the finish line of the Boston Marathon
NYPD police in New York's Times Square after security was boosted following blasts that occured at the finish line of the Boston marathon
Members of the Houston Astros (including Chris Carter, centre) observe a moment of silence for the victims involved in the explosion at the Boston Marathon prior to the baseball game against the Oakland Athletics in Oakland, Calif.