Reports are mixed, but the latest is that the explosions occurred on Boylston Street across from the Boston Public Library. This is very near the finish line of the Boston Marathon.
A photo of one of the explosions was put on twitter. It is shown below.
Police are evacuating the area and have put the nearby Fairmont and Lenox Hotels under lockdown.
Secondary devices have been found in the area. This appears to have been a deliberate event.
At least one of the explosions is said to have come from a trash can.
Two explosions at Boston marathon finish line
From ASSOCIATED PRESS
3:05 PM, April 15, 2013
BOSTON — Authorities are investigating a report of two explosions at the finish line of the Boston Marathon.
There were two booms heard from near the finish line inside the Fairmount Copley Plaza Hotel.
Race officials locked down the hotel because of the report.
The sound of two booms, which sounded like thunder, had come a short time earlier.