BBC

Reports that a suspect has been detained over Monday’s Boston marathon bombings have been denied by US officials.

The Associated Press and CNN cited law enforcement officials as saying someone was in custody, but the Boston police department denied the reports.

Earlier, officials reportedly said a suspect had been identified from security video by the race finish line.

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 bombs

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.

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.

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.

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.

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.

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.

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http://www.bbc.co.uk/news/world-us-canada-22190353