The White House says President Barack Obama has called Boston's mayor and the Massachusetts governor to express his concern for those injured in the Boston Marathon explosions.
Obama is quoted as telling Mayor Tom Menino and Gov. Deval Patrick that his administration would provide whatever support was needed in responding to the incident.
The president was briefed on the explosions by Homeland Security adviser Lisa Monaco shortly after 3 p.m., Eastern time.
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.