FBI probes Boston Marathon 'terror' blasts
An investigation is under way after two explosions near the finishing line of the Boston Marathon left three people dead and more than 170 injured.
The FBI has taken over co-ordination of what it described as a "potential terrorist inquiry".
Security has been stepped up in a number of cities across the US, including New York and Washington.
Ian Pannell reports from Boston.
16 Apr 2013
- From the section US & Canada