The US Boston Twin Bombings: 3 die, 140 Injured

Twin blasts just seconds apart killed three people, including an 8-year-old boy, and injured more than 140 others at the Boston Marathon.

The explosions drew widespread international condemnation and prompted many major cities around the world to tighten security at a variety of sports events.

The twin bombs exploded at around 3 p.m. local time (1900 GMT) Monday within seconds of each other near the finish line of one of the world's most revered races.

The blasts killed an 8-year-old boy, and injured spectators and athletes at the scene, including a Chinese overseas student and some South African runners.

The Chinese student, who was reported to be in a coma, is studying at Boston University. The student was among 87 Chinese nationals, including 17 women, who were registered to run in the annual race.

South Africa said two of 28 South African runners who had registered for the race were wounded in the bombings.

President Barack Obama said the U.S. government has not yet got "all answers" about the explosions, but vowed to hold anyone behind the bombings accountable.

Leslie Voight, who was in Boston to attend a convention, was taken aback by the bombings.

"There's a lot of sadness on a day that's supposed to be very happy and momentous for a lot of people," Voight said.

Mark Spitzer, who ran in the race, said later that he was "shocked" by the day's events. CNN, SI