This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.bbc.co.uk/news/world-us-canada-22190353

The article has changed 9 times. There is an RSS feed of changes available.

Version 1 Version 2
Boston attacks: Suspect detained, officials tell US media Boston marathon attacks: Police deny arrest
(35 minutes later)
Investigators have detained a suspect in relation to Monday's Boston marathon bombings, law enforcement officials have told US media. Reports that a suspect has been detained over Monday's Boston marathon bombings have been denied by US officials.
The breakthrough reportedly came from security video of a man dropping off a bag on the street near the race's finish line, before walking away. The Associated Press and CNN cited law enforcement officials as saying someone was in custody, but police and the FBI in Boston denied the reports.
The twin blasts killed an eight-year-old boy, a woman aged 29 and a postgraduate student from China. Earlier, officials reportedly said a suspect had been identified from security video by the race finish line.
Officials are due to hold a press conference at 17:00 ET (21:00 GMT). A press conference is due to be held at 17:00 ET (21:00 GMT).
The Associated Press news agency cites law enforcement officials as saying that a suspect has been taken into custody.
Investigators have been sifting through thousands of pieces of evidence, ranging from video recorded on mobile phones to fragments of shrapnel removed from the victims' legs. More than 170 people were wounded in the attack.Investigators have been sifting through thousands of pieces of evidence, ranging from video recorded on mobile phones to fragments of shrapnel removed from the victims' legs. More than 170 people were wounded in the attack.
Pressure cooker bombsPressure cooker bombs
The image of a suspect came from surveillance video recorded at a department store across the street from the site of the second blast, CNN reported.
The Boston Globe newspaper reported that a surveillance camera at the Lord & Taylor store had provided police with clear footage of the area.
Earlier, the Associated Press quoted a source close to the investigation as saying that the bombs consisted of explosives placed in 1.6-gallon (6-litre) pressure cookers, one with shards of metal and ball bearings, the other with nails.Earlier, the Associated Press quoted a source close to the investigation as saying that the bombs consisted of explosives placed in 1.6-gallon (6-litre) pressure cookers, one with shards of metal and ball bearings, the other with nails.
Nobody has claimed responsibility for the bombs, which a source said were placed in black bags and left on the ground.Nobody has claimed responsibility for the bombs, which a source said were placed in black bags and left on the ground.
It has been reported that a circuit board and battery pack - parts of a triggering mechanism - were recovered.It has been reported that a circuit board and battery pack - parts of a triggering mechanism - were recovered.
And the lid of a pressure cooker, apparently blown off during the explosion, was found on the roof of a nearby building, an official said on Wednesday.And the lid of a pressure cooker, apparently blown off during the explosion, was found on the roof of a nearby building, an official said on Wednesday.
The twin blasts killed an eight-year-old boy, a woman aged 29 and a postgraduate student from China.
Doctors treating the wounded say their injuries indicate that the bombs contained metal shards and other shrapnel. A number of victims have had limbs amputated.Doctors treating the wounded say their injuries indicate that the bombs contained metal shards and other shrapnel. A number of victims have had limbs amputated.
Boston Medical Center trauma surgery chief Peter Burke said hospitals were saving "large quantities" of fragments extracted from victims for the police. They include metal, plastic, wood and concrete.Boston Medical Center trauma surgery chief Peter Burke said hospitals were saving "large quantities" of fragments extracted from victims for the police. They include metal, plastic, wood and concrete.
At least 58 of the injured have been released from various hospitals around the city, according to AP. Of those that remain, 17 patients are listed as in a critical condition.At least 58 of the injured have been released from various hospitals around the city, according to AP. Of those that remain, 17 patients are listed as in a critical condition.
The first explosion went off close to the finish line at about 14:50 local time (18:50 GMT) on Monday.The first explosion went off close to the finish line at about 14:50 local time (18:50 GMT) on Monday.
Seconds later, as rescuers were rushing to help the injured, another explosion went off nearby.Seconds later, as rescuers were rushing to help the injured, another explosion went off nearby.
The London Marathon - the next major international marathon - is to go ahead on Sunday, with police saying they have well-rehearsed security plans.The London Marathon - the next major international marathon - is to go ahead on Sunday, with police saying they have well-rehearsed security plans.
Organisers have said they will hold a 30-second silence at the start as a mark of respect.Organisers have said they will hold a 30-second silence at the start as a mark of respect.