NEW YORK -- Thousands of New Yorkers donned "I Run for Boston" bibs during a four-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 four miles along the Embarcadero on Friday. A run christened "Boston Strong San Diego" is planned for Monday.
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.