Boston explosions: People warned to stay indoors
15 April 2013 Last updated at 22:33 BST
The commissioner of Boston Police has warned people to stay indoors after a series of explosions across the city.
Two people have been killed and 23 injured after two explosions at the finish line of the Boston Marathon while a third occurred at the JFK Library in the city.
Boston Police Commissioner Ed Davis said: "We are not certain that these incidents are related but we are treating them as if they are."