U.S. President Barack Obama said on
Monday that the government has not "all answers" about who had
carried out the explosions at Boston Marathon earlier in the
afternoon, but vowed to hold those behind the incident accountable.
Endi
Urgent: Obama says to hold accountable whoever behind Boston Marathon explosions
U.S. President Barack Obama said on Monday that the government has not "all answers" about who had carried out the explosions at Boston Marathon earlier in the afternoon, but vowed to hold those behind the incident accountable. End