Live coverage of ongoing events following the Boston Marathon bomb attack which killed three people including an eight-year-old boy.
The FBI has taken charge of the investigation after more than 140 people were injured. So far no motive has been suggested.
It thought around nine people from Dorset and Hampshire were taking part in the marathon.
US President Barack Obama said: "any responsible groups will feel the full weight of justice", while there could be implications in the UK for security at Baroness Thatcher's funeral tomorrow and Sunday's London Marathon.
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