As the country struggles to cope with the devastation left behind from the Boston Marathon bombing on Monday, federal agents announced that at least one of the two bombs was made with a pressure cooker.
According to officials, the pressure cooker was packed with explosives, nails and other lethal shrapnel. Investigators also found pieces of black nylon from two backpacks that they believe the bombs were placed in.
During a news conference on Tuesday, the FBI and other law enforcement agencies urged members of the public to come forward with photos, videos or reports of suspicious behavior that they witnessed.
"The range of suspects and motives remains wide open,'' said Richard DesLauriers, FBI agent in charge in Boston. He promised to "go to the ends of the Earth to identify the subject or subjects who are responsible for this despicable crime.''
The two bombs exploded about 10 seconds apart, tearing off victims' limbs and spattering streets with blood. President Barack Obama has referenced the attack, which wounded more than 170 people and took the lives of three bystanders, as an act of terrorism. In addition, 17 victims have been listed in critical condition including a 9-year-old girl and 10-year-old boy.
Officials found that the bombs consisted of explosives put in ordinary, 1.6-gallon pressure cookers, one with shards of metal and ball bearings, the other with nails, according to a insider close to the investigation who spoke on the condition of anonymity.
However, investigators said they have not yet determined what was used to set off the explosives.
Pressure-cooker explosives have been used in international terrorist attacks by Al-Qaida, but U.S. officials warned Americans not to jump to conclusions being that information on how to make the bombs can easily be found online.
DesLauriers said there had been no claim of responsibility for the attack.
Back in 2010, the Pakistani Taliban, claimed responsibility for the bomb attempt in Times Square. However, they have denied any part in the Boston Marathon attack.