BOSTON - Religious gatherings across the Boston area, and runners around the world, are honoring victims and responders of the marathon bombings that have left the city shaken since Monday.
Cardinal Sean O'Malley said during a Mass at the Cathedral of the Holy Cross Sunday that it was difficult to understand what was going through the suspects' minds or "what demons were operating."
Photographs of the three people who died in Monday's explosions and a police officer who was fatally shot days afterward sat on an altar, their faces illuminated by glowing white pillar candles.
Also Sunday, a Boston synagogue opened its doors to worshippers from Trinity Episcopal Church, which sits in the shadow of the marathon finish line and remains closed.
An interfaith service was also held Sunday near the finish line.
In New York, thousands of people wore "I Run for Boston" bibs during a 4-mile run Sunday in Central Park, one of a number of races held around the world in support of the victims of the marathon bombings.
"It was really quite a powerful morning," said Mary Wittenberg, CEO of the New York Road Runners. "We dedicated the race to Boston."
More than 6,000 runners took part in Sunday's City Parks Foundation Run for the Parks, which was planned before Monday's bombings.
Organizers turned it into a show of solidarity by selling "I Run for Boston" T-shirts with proceeds going to the One Fund Boston, the official fund for those affected by the bombing.
Other "Run for Boston" events have taken place around the U.S. and the world, with many runners wearing blue and yellow, the official Boston Marathon colors.
More than 500 runners gathered in St. Louis on Saturday for a Unity Run. In San Francisco, about 400 people ran 4 miles along the Embarcadero on Friday. A run christened "Boston Strong San Diego" is planned for Monday.
In Michigan, runners braved sub-freezing temperatures and a partly flooded course Sunday in the Lansing Marathon, which was dedicated to the Boston victims. In Burlington, Vt., a 5-kilometer walk-run on Saturday raised more than $10,000 for Massachusetts General Hospital's emergency fund and One Fund Boston.
Sunday's London Marathon started with tributes to the Boston victims and a moment of silence. The London event was the first major race since the twin bombings in Boston killed three people and injured more than 180 others.
In New York, security for Sunday morning's run was tightened in response to the attacks.
Runners were told not to bring bags. Instead, clear plastic bags were provided by race officials for those who brought belongings.