The two bombs that exploded during the Boston Marathon yesterday were made out of 6-liter pressure cookers, an unidentified source briefed on the investigation told the Associated Press.
One of the bombs contained metal and ball bearings in a pressure cooker, while the other bomb contained nails in a pressure cooker, the source said.
The pressure cookers were then hidden in black bags and placed on the ground, but no word on how they were detonated.
A second unidentified source could only confirm to the Associated Press that at least one of the bombs was made out of a pressure cooker.
The two bombs killed three people and injured 170 others.
The Associated Press notes that the May 2010 Times Square attempted bombing was a pressure cooker.
The Boston bombings appear to have originated from foreign terrorist(s) as pressure cooker bombs have been used by terrorists in other countries such as Afghanistan, India, Nepal and Pakistan.
"We will go to the ends of the Earth to identify the subject or subjects who are responsible for this despicable crime, and we will do everything we can to bring them to justice," stated FBI agent Richard DesLauriers.
Source: Associated Press