“Massive casualties” are reported after a pair of explosions near the finish line of today’s Boston Marathon.

Reporters at the scene noted blown out storefronts at Boylston and Exeter streets, and were urging people to stay away from Copley Square.

The hotel that serves as race headquarters was locked down.

Patients were flooding in to the emergency room at Mass General Hospital. Numerous grievous injuries were reported.

Casualty reports varied. At one point three people were reported dead by Boston Police. Now that number is down to two dead, 23 injured.

Those runners who had not yet finished the race were not allowed to as authorities cancelled the rest of the race.

Police in Los Angeles, New York City, London and other cities worldwide are stepping up security as a precaution.

A senior U.S. intelligence official says two more explosive devices have been found near the scene of the Boston marathon where two bombs detonated earlier. The official told the Associated Press the new devices were being dismantled. It’s not yet clear what kind of devices were found. The official said the first two did appear to be bombs. According to the official, it’s not clear what the motive was or who may have launched the attack.