President Barack Obama says Monday's bombings along the route of the Boston Marathon were an act of terrorism. Officials say three people died in the explosions and more than 170 were injured.
Obama told reporters at the White House the bomb attack in Boston was a "heinous and cowardly act" and for the first time described it as an act of terrorism.
"Anytime bombs are used to target innocent civilians, it is an act of terror," the president said. "What we do not 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. That is what we do not yet know and clearly we are at the beginning of our investigation."
Meanwhile in Boston, federal, state and local investigators briefed reporters at a hotel not far from the scene of the bombings that rocked the city Monday.
FBI Special Agent in Charge Richard DesLauriers, far right, speaks as Boston Mayor Thomas Menino, left, and Mass. Gov. Deval Patrick, center, listens during a news conference in Boston, April 16, 2013.
The FBI agent in charge of the investigation, Rick Deslauriers, says officials have received “voluminous tips” in connection with the bombings and investigators will follow the trail of evidence wherever it leads.
“This will be a worldwide investigation. We will go where the evidence and the leads take us," Deslauriers announced. "We will go to the ends of the Earth to identify the subject or subjects who are responsible for this despicable crime and we will do everything we can to bring them to justice.”
Leaders from around the world, especially countries wracked by violence targeting civilians, are condemning the twin bombings at the Boston Marathon, which killed three people and wounded more than 100 others.
Pakistan's Foreign Office condemned what it called the "terrorist attacks," saying the government and Pakistani people are "deeply shocked and saddened" by the "despicable act."
Pakistan has been battling a Taliban insurgency since 2007, and as a result has seen many bombings in public places, attacks that have claimed thousands of civilians' lives. he Pakistani Taliban, which has in the past claimed responsibility for attempted attacks in the United States, denied having any role in the Boston bombings.
In neighboring Afghanistan where the Taliban is blamed for most of the Afghan war civilian casualties, President Hamid Karzai strongly denounced the Boston attack and offered condolences and sympathies to the families of the victims.
In India, Prime Minister Manmohan Singh responded by expressing his "solidarity with the American people in the struggle against terrorism." In 2008, India's commercial capital Mumbai was under siege for days as heavily armed militants launched coordinated gun and bombing attacks across the city.
Somali President Hassan Sheikh Mohamud also spoke out against the attack on the innocent athletes and their supporters, calling the bombing "the most depraved and vicious act of cowardice." At the same time, his country's Islamist militant group al-Shabab mocked online those injured and killed.
United Nations Secretary General Ban Ki-moon lamented the "senseless violence," saying the incident was even more appalling because it took place at an event known "for bringing people together from around the world in a spirit of sportsmanship and harmony."
The Organization of Islamic Cooperation strongly condemned what it called the "cowardly attacks." In a statement, the OIC said it has fought against terrorism in all its forms, and offered its condolences, prayers and support to the people of Boston.
Meanwhile from the Vatican, Pope Francis "deeply grieved" the news of the attacks and prayed that all Bostonians "will be united in a resolve not to be overcome by evil, but to combat evil with good."
European Union President Herman Van Rompuy condemned what he called the "appalling attacks" and expressed confidence that the perpetrators will be brought to justice.
NATO Secretary General Anders Fogh Rasmussen also expressed "deep shock" at the attack and offered condolences to those affected. In a statement, he said his thoughts are with the people of Boston and all of the United States