BOSTON  Two people were killed and 23 were injured after two bombs detonated near the finish line of the Boston Marathon Monday.

Competitors and race organizers were crying as they fled the chaos. Bloody spectators were being carried to the medical tent that had been set up to care for fatigued runners.

Boston police said a third explosion had occurred at the JFK Library at about 4:30 p.m. and two additional explosive devices were found near the marathon route. They were being dismantled.

Witnesses reported hearing two explosions, just seconds apart, on the north side of Boylston Street near the marathon’s photographers bridge just before 3 p.m. Fox 25’s Maria Stephanos, whose husband had just completed the race, reported that at least one of the explosions appeared to come from the inside of a building, possibly Marathon Sports.

“I was right there, I saw a plume of smoke coming from a building,” said Stephanos.

Video from SkyFox showed blood on the ground near the finish line. A Fox 25 photographer at the scene reported seeing a number of victims with lost limbs.

The Boston Marathon’s Twitter account reported that the explosions were as the result of bombs being detonated.

Massachusetts General Hospital officials said they had taken in 19 patients, six with critical injuries. Nine patients were taken to Tufts Medical center.

The Boston Marathon was suspended. Runners were being stopped at mile 26.

The Massachusetts Ave bridge was closed and the MBTA had suspended service on the B and C lines of the Green Line.

The air space over Cooley Square was closed and SkyFox was ordered out of the area at about 3:40 p.m.