- 187 updates
US media is reporting that an arrest has been made in connection with the Boston bombings. There is yet to be any official confirmation.
Boston bombing investigators believe they have identified a suspect from security video taken before the blast, CNN and the Boston Globe reports.
"Substantial progress" is being made in the Boston bombings investigation, according to police officials.
White House Press Secretary Jay Carney has said the First Lady Michelle Obama will join the US President his visit to Boston tomorrow, following the marathon bombings.
US Secretary of State John Kerry became emotional today as he told congress that a friend's granddaughter is at risk of losing both of her legs following the Boston bombings:
He also told members: "It's impossible for me to express my sadness and my anger...over those terrible events. It's hard to believe a Patriots' Day holiday, which is normally a time of festivities, turned into bloody mayhem."
He added: "But we're going to find out who did this.The police work being done is extraordinary. The FBI is remarkable. There's a great deal of forensic evidence. We're hopeful that we can bring people to justice."
A Boston-based TV station, 7News, has released a photograph that appears to show a bag at the centre of one of the explosions in the city.
In the first image, a white bag can be seen by the side of the road:
The second image, taken some time after the blast, the bag is no long visible and debris litters the immediate vicinity. It has been blurred because of the graphic content.
The photographer who sent in the images said they were taken an hour or more apart.
According to the station, another series of images sent in by a viewer appear to show a man "fleeing from the scene" immediately following the blast.
Dr Peter Burke added that two patients being treated at the Boston Medical Centre are still in a critical condition. A further 10 are seriously injured, and seven are in a "fair" condition.
"Most patients are making good progress," he added.
A surgeon has said that the fragments found embedded in people injured in the Boston Marathon explosions are made from a range of materials including metal, plastic and wood.
Dr Peter Burke, the Chief of Trauma Services at Boston Medical Centre, told reporters that 19 patients remain at the hospital and that their injuries were mostly related to shrapnel from the blasts affecting their "lower extremities".
Those injured in the twin explosions were taken to several hospitals, of which the Boston Medical Centre is one.
Federal investigators have discovered the lid to a pressure cooker which they believe was used in the Boston Marathon bombings on the roof of a nearby building, CNN reports.
The article cites a "federal law enforcement source with first-hand knowledge of the investigation".
Boston TV station 7 News claims to have identified a bag left by the side of the road just before the blast in video footage. Before and after shots suggest that the bag was positioned at the centre of one of the blasts.
The images have been passed on to investigators.
An episode of US cartoon Family Guy that depicts mass deaths at the Boston Marathon has been pulled from websites and will not air in the near future, the Associated Press reports.
The episode features the main character Peter Griffin having a flashback to the marathon in which he is driving towards the finish line, mowing down other runners.
Fox spokeswoman Gaude Paez is cited saying that the episode has been removed from websites Fox.com and Hulu.com and that there are no plans to air it again soon.
The show's creator, Seth MacFarlane, also tweeted his disgust at a You Tube clip in which the scene is edited with another in which Griffin uses his mobile phone to accidentally trigger explosions:
Latest ITV News reports
New photos of the suspects identified by officials as Dzhokar A. Tsarnaev, 19 and Tamerlan Tsarnaev, 26 have been released.
The FBI has released pictures and video of two suspects in the Boston Marathon bombing, seeking the public's help.