The lid of a pressure cooker was found on a roof near the scene of the Boston Marathon bombings, a federal law enforcement official with firsthand knowledge of the investigation tells CNN.
One of the bombs was housed in a pressure cooker hidden inside a backpack, the FBI said in a Joint Intelligence Bulletin. The device also had fragments that may have included nails, BBs and ball bearings, the agency said.
The second bomb was also housed in a metal container, but there's not enough evidence to determine whether it was also in a pressure cooker, the FBI said.
Discovery of the lid could yield vital clues as to the origin of the bomb.
Follow coverage of breaking news on CNN TV, CNN.com and CNN's mobile apps.
Anthony Bourdain Parts Unknown
New Show. No Boundaries.
Sundays at 9pm ET/PT on CNN
You have opted-in to receive this e-mail from CNN.com. To unsubscribe from Breaking News e-mail alerts, go to: http://cgi.cnn.com/m/clik?l=textbreakingnews
One CNN Center Atlanta, GA 30303
(c) & (r) 2013 Cable News Network