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.
In this image from video provided by WBZ-TV, spectators and runners run from what was described as twin explosions that shook the finish line of the Boston Marathon, April 15, 2013.
An emergency responder and volunteers, including Carlos Arredondo in the cowboy hat, push Jeff Bauman in a wheel chair after he was injured in an explosion near the finish line of the Boston Marathon April 15, 2013.
Medical workers transport the injured across the finish line during the 2013 Boston Marathon following an explosion, April 15, 2013.
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion, April 15, 2013.
One of the blast sites on Boylston Street near the finish line of the 2013 Boston Marathon is investigated by two people in protective suits in the wake of two blasts in Boston April 15, 2013.
Runner John Ounao cries when he finds friends after several explosions rocked the finish of the Boston Marathon, April 15, 2013.
A police officer clears Boylston Street following an explosion at the finish line of the 2013 Boston Marathon, April 15, 2013.
Medical workers aid a wounded woman at the finish line of the 2013 Boston Marathon following two explosions there, April 15, 2013.
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, April 15, 2013.
A woman is comforted by a man near a triage tent set up after explosions went off at the 117th Boston Marathon, April 15, 2013.
A Massachusetts state police officer guards the area containing the medical tent, rear, following an explosion at the 2013 Boston Marathon, April 15, 2013.
An unidentified Boston Marathon runner leaves the course crying near Copley Square following an explosion, April 15, 2013.
A Boston police officer wheels in injured boy down Boylston Street as medical workers carry an injured runner following an explosion during the 2013 Boston Marathon, April 15, 2013.
Justine Franco of Montpelier, Vermont, holds up a sign near Copley Square looking for her missing friend, April, who was running in her first Boston Marathon, April 15, 2013.
President Barack Obama leaves the podium after speaking in the press briefing room at the White House, April 15, 2013, following the explosions at the Boston Marathon.