Following two explosions at the finish line of the Boston Marathon, Boston police said during a press conference there was a third explosion at Boston's JFK library that appears to be related to a fire.

Police said during a press conference just before 5 p.m. that the explosion at JFK library occurred at roughly 4:30.

It appears the blast might have been related to a 3 p.m. fire inside JFK library that the the Dorchester Reporter reported was not related to the marathon explosions.

The AP tweeted earlier that an intelligence official said two unexploded devices were found at the marathon.

Time's Andrew Katz tweeted earlier that police were investigating reports of bombs in other parts of the city.

Citing a police scanner, Katz tweeted before the 5 p.m. press conference that there was an "incendiary device" possible at JFK Library as well as "another device" in front of Boston's luxury Mandarin hotel.

Boston Phoenix reporter Chris Faraone tweets a police officer near the finish line said this: "There are secondary devices that have been found and are unexploded."

The police scanner said that police were going to do a third, controlled explosion on the 600 block of Boylston Street.

The FAA has announced that no airplanes will be allowed to leave Boston's Logan Airport.

We'll update you with more developments soon.