Pressure cooker clues emerge in Boston Marathon bombing investigation

  • Bombs that exploded at the Boston Marathon on Monday may have been packed in pressure cookers, according to investigators on Tuesday.

    Speaking at a press conference, FBI Special Agent Richard DesLauriers said that pieces of nylon had been recovered from the scene along with pieces of ball bearings and nails that were "possibly contained in a pressure-cooker device".

    Photographs from a joint Homeland Security and FBI probe show the remains of a dark-colored backpack, a detonation device and pieces of metal.

    Three people died and more than 170 were wounded after two bombs went off near the finish line of Monday's race.

    Doctors treating patients said their injuries indicated that the bombs contained shards of metal and other shrapnel. A number of victims had had to have their limbs amputated.

    President Barack Obama is due to travel to Boston on Thursday for a memorial.

    Know about the site of Boston Marathon location through Boston Marathon Explosion Map 

    Tagged as: explosive investigation, Pressure cooker clues, Boston Marathon, Boston Marathon bombing investigation