President Barack Obama called the Boston bombings an “act of terror” on Tuesday, but said it is not clear yet whether the twin blasts were the work of a foreign or domestic group or a “malevolent individual.”
In an appearance in the White House briefing room, Obama urged Americans to be vigilant and to watch for suspicious activity a day after the two explosions rocked the finish line of the Boston Marathon, killing at least three people and wounding more than 170 more.
Obama, briefed by FBI Director Robert Mueller, Homeland Security Secretary Janet Napolitano and other national security aides, said there is still much to be investigated in what was the worst attack on U.S. soil since 9/11.
There is no sense of a motive and no indication as to who planted the bombs and detonated them, he said, condemning it as a “heinous and cowardly act.”
“Any time bombs are used to target innocent civilians, it is an act of terror,” Obama said. “What we don't yet know, however, is who carried out this attack or why, whether it was planned and executed by a terrorist organization — foreign or domestic — or was the act of a malevolent individual.”
The president ordered the U.S. flag atop the White House lowered to half-staff in memory of the victims.
He said the investigation into the bombings is just beginning.
“It will take time to follow every lead and determine what happened. But we will find out,” Obama said. “We will find whoever harmed our citizens and we will bring them to justice. We also know this: The American people refuse to be terrorized.”
A Boston-area apartment was one focus of a wide-ranging police investigation on Tuesday as authorities pursued clues into who carried out the bombing attack.
Police overnight searched an apartment in Revere, about six miles northeast of Boston, that was the home of a person whose connection to the event is under investigation, law enforcement sources said.
A stretch of Boylston Street near the race's finish line and the blocks around it were closed to traffic as police searched for evidence of the identity of who placed the bombs packed with ball bearings to maximize casualties.
In Boston, dozens of police and National Guard vehicles were parked around the cordoned-off area, which was empty of cars and pedestrians as authorities hunted for clues.
A banner that had marked the race's finish line still hung over the deserted street.
Police searched the Revere residence of a Saudi Arabian student who was injured in the blasts, according to law enforcement sources. One of the sources said the student was the main lead investigators are looking into, but he has not been labeled a suspect.
Katherine Gulotta, a spokeswoman for the FBI, which has taken over the lead in the investigation, declined to confirm or deny the reports.
Obama was updated on the investigation overnight by his homeland security and counterterrorism aide, Lisa Monaco.
White House officials and investigators said it was too early to say whether the Boston attacks were carried out by a foreign or homegrown group, or to identify a motive.
Hospitals in the Boston area were planning surgeries for some of the victims, many of whom sustained lower leg injuries in the blasts, said Dr. Peter Fagenholz, a trauma surgeon at Massachusetts General Hospital.
“We're seeing a lot of shrapnel injuries” from small metal debris, Fagenholz told reporters outside the hospital. Doctors there treated 29 people, of whom eight were in a critical condition.
An 8-year-old boy was among the dead, officials said, and a 2-year-old was being treated at Boston Children's Hospital for a head wound.
Major Cities on Alert
The blasts put police on alert in major cities across the United States, including Washington and New York City, the sites of the 9/11 attacks.
The annual Boston Marathon, held since 1897, attracts an estimated half-million spectators and some 20,000 participants every year.
In Britain, organizers said the London Marathon would go ahead on Sunday despite the Boston attack, but security was being reviewed.
The Madrid Marathon also planned to proceed on Sunday, but security plans were under review, a Spanish official said.
“After what happened in Boston we'll have to look into whether we need to review our plans. Since yesterday we are coordinating with municipal security and local government,” Pedro Rumbao, director of the Madrid marathon, told Spanish National Radio.
Runners who had traveled to the city for the race remained in shock Tuesday morning.
Pat Monroe-DuPrey of Winter Haven, Fla., ran with his wife, Laura, in a trip to mark their 10th anniversary after being married during the race.
He said he did not know what to make of the blast, which came as he was finishing the race in a state of exhaustion.
“You don't have a brain at 26 miles,” Monroe-DuPrey said. “They got us off the course, and then I was panicking.”
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