The White House says President Barack Obama has been notified about the explosions at the finish line of the Boston Marathon.
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.
"Apparently there has been a bombing," Biden said. "I don't know any of the details of what caused it, who did it. I don't think it exists yet. But our prayers are with those people in Boston who suffered injury."
Shortly after the explosions, Secret Service 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.
The White House was not on lockdown and tourists and other onlookers were still able to be in the park across the street from the executive mansion.