Boston - New details about the Boston bombing are being released.
This comes as federal authorities are intensifying their probe.
The FBI and Boston police are zeroing in on how Monday's bombing was carried out.
Forensic specialists and dogs trained to detect explosive devices are continuing to search the scene of the blasts.
A command post has also been set up where 1,000 officers are conducting interviews and gathering details.
Authorities have already received nearly 2,000 tips from around the world.
But the range of suspects and motives remains wide open at this time.
They are continuing to ask members of the public to come forward with photos, videos, or anything suspicious they may have seen or heard.
We are also learning more about the three victims killed in the bombing.
8 year old Martin Richard loved to run and play outside.
29 year old Krystle Campbell is described by her mother as having a "heart of gold."
The third victim was a Chinese graduate student at Boston University.
Among the 183 people injured, nearly 100 have been released from the hospital.
So far, authorities say no connection has been made to any terror group.
A senior U.S. official says there is no reporting indicating any reaction from Al Qaeda.
The Pakistani Taliban has come forward saying it was not involved in the attack.
The Saudi Embassy in the United States says there is no evidence of involvement of any Saudi national in the bombings.
President Barack Obama described the bombing as a terrorism act but says it's unclear whether it was the work of a group or individual.
The FBI has just released photos of bomb parts used in the Boston marathon explosions.
The agency says evidence indicates the bomber packed a pressure cooker with explosives, nails and ball bearings and hid it in a back pack.
They also say the second bomb was in a metal container.
All of the items have been sent to the FBI headquarters laboratory in Quantico, Virginia.
The FBI also plans to reconstruct the devices at their headquarters.