
President Barack Obama on the phone with FBI Director Robert Mueller discussing the Boston Marathon explosions. (White House Photo)
President Barack Obama said "we still do not know who" caused the fatal explosions at the Boston Marathon, but he avoided using the term "terrorism".
"We will get to the bottom of this," Obama said in a statement at the White House. "We will find out who did this and we will hold them accountable."
"Any responsible individuals, any responsible groups will feel the full weight of justice," Obama said.