(CNN) — New developments:
– A knowledgeable source called the bombs “crude.”
– The bombs appear to have been inside metal pressure cookers that were in backpacks, a federal law enforcement official with knowledge of the investigation told CNN.
– Boston-area hospitals have discharged at least 51 of the at least 174 people wounded in Monday’s attack, according to a CNN tally.
– “My dear son Martin has died from injuries sustained in the attack on Boston,” said Bill Richard, father of the 8-year-old fatality, in a statement. His wife and daughter were wounded in the attack. “I ask that you continue to pray for my family as we remember Martin. We also ask for your patience and for privacy as we work to simultaneously grieve and recover.”
– The Virgin London Marathon will mark 30 seconds of silence before this Sunday’s race and is urging runners to wear a black ribbon to mark the Boston events.
– The flags at the White House, like those on Capitol Hill on Monday, were lowered Tuesday to half-staff.
– One of the two bombs that exploded Monday near the Boston Marathon finish line was inside a metal pressure cooker that was in a backpack, a federal law enforcement official with knowledge of the investigation told CNN.
– A law enforcement official said it was “likely, but not certain” that a timing device was used and that the bomb was not activated by a cell phone.
– At least two Saudi nationals were wounded in the Boston Marathon bombings, a Saudi Embassy official told CNN. Neither is a suspect in the attack, the Saudi official said, citing U.S. officials.
– One is a student, 20, who suffered shrapnel wounds and was questioned as a possible witness, the source said.
– The other is a medical student who was at the marathon with her husband and child, the source said.