A doctor at a hospital where victims of the Boston Marathon explosions were taken says an X-ray of one victim he saw showed what could be small ball bearings throughout the injury.
Three people were killed and more than 140 injured by two explosions just seconds apart near the finish line Monday.
Dr. Stephen Epstein of the Department of Emergency Medicine at Beth Israel Deaconess Medical Center says in an email the X-ray of a leg he saw has "what appears to be small, uniform round objects throughout it -- similar in the appearance to BBs."
He says exactly what the objects are remains to be determined.
A spokeswoman as Massachusetts General Hospital said Tuesday that doctors there treated "everything from cuts and bruises to amputations."