Carnage at Boston Marathon
An explosion rips through the air as runners in the Boston Marathon head towards the finishing line.
Two bombs tore through crowds near the race's finish, killing three people, injuring many others and triggering a massive hunt for those behind an attack the White House said would be treated as an "act of terror".
The first wave of runners set off as they compete in the Boston Marathon.
Supporters cheer on participants.
Boston Marathon Men's division winner Lelisa Desisa Benti, of Ethiopia, and women's division winner Rita Jeptoo, of Kenya, pose for a portrait with the trophy.
Police and runners react to an explosion going off near the marathon finishing line around four hours into the race.
Smoke rises behind police and participants following the double blast.
A runner is escorted from the scene after explosions went off.
A marathon participant with a bloodied leg is taken from a triage tent in a wheelchair.
A SWAT truck transports officers to the scene.
FBI agents arrive after the explosions.
Blood is spattered on the sidewalk as men in bomb-disposal suits investigate the site of the attack.
Pedestrians watch as police gather near the medical tent after the bombs went off.
A man comforts a woman near a triage tent.
A woman talks on the phone following the attack.
A woman covers her mouth and cries.
An officer gives directions to a participant after the bombs detonated.
SWAT officers stand guard.
National Guard troops stand near the Boston Common before going on a sweep near the scene of the bombings.
A national guardsman waits in a school bus near the finish line.
Unclaimed runners' bags from the Boston Marathon lie in a pile.
