President Obama called the events in Boston an "act of terrorism," on Tuesday for the first time since two bombs exploded at the finish line of the Boston Marathon. The FBI is investigating the "heinous and cowardly act," the president said.
"Any time bombs are used to target civilians is an act of terror," Obama said from the White House Tuesday.
"Americans refuse to be terrorized," he said.
The president spoke of the heroism seen in the direct aftermath of the tragedy—of exhausted runners who kept running to hospitals to donate blood, the priests who opened churches, and the Bostonians who opened their homes to those affected by the attack.
"If you want to know who we are, what America is, how we respond to evil, this is it: selflessly, compassionately, unafraid," Obama said.
Three are dead—including an 8-year-old boy—and more than 170 are wounded from two explosions that went off just after 2:50 p.m. Monday. What the authorities don't know, Obama said, is who is responsible or why. Authorities are looking into whether the attacks were planned by a terrorist organization—foreign or domestic—or carried out by a "malevolent individual."
"We don't have a sense of motive," Obama said. "Everything else is speculation."
The president emphasized that law enforcement authorities were still in the beginning stages of investigations and it might take some time before answers came to light, but "we will find whoever harmed our citizens, and we will bring them to justice."
FBI and Boston law enforcement authorities said earlier Tuesday that they were following up on "a variety of leads," but that no one was in custody.