Boston police say three people were killed and over 140 people were hurt when a pair of bombs exploded near the finish line of the Boston Marathon.
A person familiar with the situation tells The Associated Press that an 8-year-old-boy has been killed.
The blasts shattered the end of the race Monday, sending authorities out on the course to carry away the injured while stragglers in the 26.2-mile race were rerouted away from the smoking site.
One woman says she was waiting for her husband to cross the finish line, and, in her words, "it just blew." She described it as "a loud boom, and then glass everywhere." Cherie Falgoust says something hit her head, and she "just ducked."
A runner, Laura McLean of Toronto, says she heard two explosions outside the medical tent. She says, "There are people who are really, really bloody." McLean says, "they were pulling them into the medical tent."
The explosions took place about three hours after the winners crossed the finish line. The second one could be heard a few seconds after the first one.
British police say they are reviewing security plans for Sunday's London Marathon. It's the next major international marathon. A London Metropolitan Police spokesman says police are working with marathon officials to review security plans.
The White House says the administration is in contact with state and local authorities and directed his administration to provide whatever assistance is necessary in the investigation and response.
Vice President Joe Biden was on a conference call with gun control activists when staffers turned on televisions in his office Monday to view coverage of the explosions. Biden said during the call that his prayers were with those who suffered injuries.
Secret Service has shut down Pennsylvania Avenue outside the White House, cordoning off the area with yellow police tape. Several Secret Service patrol cars also blocked off the entry points to the road.