FBI 'following up on a variety of leads' to Boston bombings
As the FBI launched a hunt for those responsible for the Boston Marathon bombings, US President Barack Obama said: “We will find out who did this. We’ll find out why they did this. Any responsible individuals, any responsible groups, will feel the full weight of justice.”
There were no immediate claims of responsibility for the attack, the most serious in the US since the 9/11 atrocity.
